I don't follow your argument.  How does Nintendo exclusivity affect PC sales?  This 8m milestone was announced shortly after the game launched on PC.  Also, your comment may seem premature in a few weeks, as I would expect more announcements when it crosses 9m, 10m, etc....  Wouldn't you want to see PC sales slow down first before we get an idea of what the lifetime total is?

Well it will at least pass 10 million in total, though looks like it won't pass 10 million on Switch alone as I had figured. Though it should get close on Switch, with the expansion coming this year plus likely price discounts in the future.

But Capcom now has a great thing going where they have an extremely popular World series on Playstation and a very popular Rise series on Nintendo. Makes sense to keep each one separate so they can each be made well specifically for the two respective systems going into the future of the MH ip. MH in japan of course has way more competition on Nintendo systems than it does on PS systems because most large franchises in Japan are on Nintendo, and it feels like World is more AAA than Rise too, which no doubt accounts for some of the sales difference. But MH is now a very strong franchise with two separate series that sell very well on both Playstation and Nintendo, which is great for MH and gamers alike.

Nintendo finally got Dragon Quest back (albeit very late), still missing Final Fantasy, and now has a main MH series as well. Those were the three huge Japanese franchises Nintendo consoles had been missing out on for a long time. If anything, MH and DQ should become even bigger franchises on Nintendo in the future as the Nintendo fanbase starts getting used to these serie and these companies see that these games are worth a lot of effort and very profitable on Nintendo. Good times for Nintendo gamers!

With World they specifically waited until it crossed 10 million, it took 11 days

If Capcom believed they could reach 9 million anytime soon they would have waited to announce 9 million. 9 million will probably take quite a while (probably more than a month) to be surpassed, hence they announced what they had (8 million) 

Just so you know, aligned the Rise PC version released later than the World PC version.

I still don't follow your argument.  Could you address my question please?  How does Nintendo exclusivity affect PC sales?  All your post seems to do is say that PC sales are poor.

Oh, it's not that Nintendo exclusivity affect PC sales, but if Nintendo versions end selling less on PC maybe it's more cost effective to release a downgraded version for Nintendo consoles after a PC version. Not indeed a downgraded version in the sense of scalling down, but a game made from the ground for Nintendo but the same game nonetheless. For instance Dragon Quest 11, it's pretty much the same game but with a less detailed graphics and resolution (in reality the Switch version added extra content) but it was build from the ground to run on Switch

The reason to release 2 MH is to profit from people buying both games. It's something that seems likely to long therm fans, mainly JP audiences. But if the game rely heavily on Multi-player (which MH absolutely does) then less avid fans will just pick their preferred game. Between World and Rise, PC gamers choose World, making Rise PC release a bit redundant. Maybe it would be better to have a "World 2" made for Switch, instead of a Rise 2 made for Switch 

Wtf this argument has no logic the 8m sales just announced are given as the PC version releases this likely indicates almost all the 8m is on NS alone and PC sales haven't been fully tracked yet, this means by developing for the NS ground up they were rewarded with nearly 8m sales and counting which says do the opposite of what you're saying here.

World was the first PC MH released in the west many of its players didn't even know what kind of game it was while with Rise they do all they knew with World was the massive marketing push, PC outlets who have reviewed Rise prefer it over World as a game and even then why should what PC players prefer affect Rise 2 being made as Rise on NS is the second highest selling MH game on a single platform. If anything Rise reinforced that Nintendo exclusivity still works fine for the series and if a PC version falls short it means the is no need for one in future for this line in the series.

So why instead of spending money to make 2 games, why not release a single game to all platforms and support them all at the same time to get the same money from in game purchases and DLC. A consolidated game per generation with everybody playing together is about as lucrative a franchise can be. It will miss some Nintendo sales, because people will prefer to buy it on PC or Playstation, but will cost them far less money for develop too 

Because the Switch simply isn't as powerful as the other consoles, yet it still clearly has made Capcom quite a bit of money on the software side. In addition, I would be willing to bet that MH: Rise received less discounted opportunities than MH: World did. Physically for Black Friday World was available for $20 at its lowest in 2018 whereas Rise was available for $25 at it's lowest in 2021. Digitally, World was available for $30 at its lowest in 2018 whereas Rise went down to just $45 at it's lowest. 

This isn't to take away from Worlds sales. This is just to bring context to the fact that MH: Rise still made Capcom a tidy profit. If they can capitalize on the separate Nintendo purchases in addition to the purchases from PS and Xbox it will bring them overall more profit. Whereas, making a MH game for all consoles decreases what you are able to do on the Series X/PS5 side and/or decreases the overall quality of the Switch port (MH: Rise looks great, MH: World port would probably be way more blurry and lower average framerate). People WILL expect more from their newest boxes than an upressed Switch game. 

That's how I view it at least. 

Because they cater to different audiences, World is similar to prior console MH while Rise is structure more like the Freedom series so more suited to what MH enthusiasts, you can't have it both ways so the result is one platform will suffer in its version. By building specifically for the platform ground up they maximized sales more than what you're suggesting as PS and NS are almost 18m sales by themselves because the people who want what World brings aren't the same as the people who want what Rise brings all your suggestion does is ignore an entire section of the fanbase and lessen potential sales instead of increasing them.