It is quite simple to estimate the cost of a game at least for the ballpark.
Size of the team, time to develop (just look at the time of release minus time of the last game released) and average salary.
When we talk about indies - B - A - AA - AAA let's say something like 100k 1M 10M 30M+ budget (or if you want to define other boundaries) since they have a very big gap between them you can easily separate as some already made here.
And even if you don't want to use absolute numbers you can still look at the game in hand and see if it have all the scope for AAA or not.
I don't know why do we need 2 reaction thread for the Octopath Traveller though (this one even being a reaction to the reaction, on the platform holders games being AAA).

Content value is in big part quite subjective - that's why BotW is for me worst 3D Zelda (bar MM, which I never liked due to time gimmick), despite being able to provide so many hours of gameplay, and for many others it's best Zelda and even best game ever made - yet few will try to argue its production values.

I can pick so many great games with great content value (some of them even genre defining titles) and nowhere near as great production values, but no, I will never call any of them AAA games - even if many of them are in my Top 10 of all time.

While I agree that conflating "AAA" with quality is a mistake -- "AAA" in the modern games industry is more of a black eye than anything, in my mind -- the term does have a lot to do with high productions values and development/advertising budget, along with anticipated sales.

It means exactly what people think it means.

AAA game is the same as like a big hollywood blockbuster movie.

Quality means nothing. Just means a shit ton of money was spent on the game. The movie/game can suck or bomb in sales, but that doesn't make it not a blockbuster/AAA game.

I think that for movies they need to sell a lot to be blockbusters (movies that the waiting line would go over the block), but yes generally they'll all be those high budget and usually action movies.

Then we as gamers need to word things better when making certain requests.  Like instead of saying, "I want more 3rd party AAA games on Switch," people should say  " I want more QUALITY 3rd party games on Switch."

Most people would rather have games like Octopath Traveler, Mario Plus Rabbids, or Fortnite on the console than many of the other lackluster AAA games.  They would be nice to have, and people would brag, but quality seems to be trumping games that cost more to make.  Even the better AAA games that do come to Switch seem to struggle despite people wanting them on the system.  DOOM and Wolf 2 for example, while great ports, lacked in quality when compared to their counterparts.  But cheaper games that are just as good like Crash, Sonic Mania, Octopath, etc are selling like hotcacks.  So when most Switch gamers beg for more AAA 3rd party games, they are not truly asking for what they want based on sales numbers.

I am not saying you are wrong, it is just a difference of perspective.  One party is looking at it from a consumer standpoint (mainly Nintendo fans) while the other is looking at it from a development standpoint.  Both sides have a point, and while the development standpoint seems to be the traditional term, a difference in perspective is causing a lose in translation when the topic is discussed.

I'm a little spoiled so I want both. High production value and High quality.

But you are right when looking at average titles PS4/X1 sell more the high budget than Switch but Switch have a healthy number for quality lower budgets.

I'm guessing AAA is like gta, AA is like fortnite, and A is like shovel knight

I did a google search and came up with the following:

As per Wikipedia: In the video game industry, AAA (pronounced "triple A") or Triple-A is a classification term used for games with the highest development budgets and levels of promotion. A title considered to be AAA is therefore expected to be a high quality game or to be among the year's bestsellers.

Sure, it's Wikipedia, but all of the following results said the same thing in slightly different words. So there is a perception of expected sales or quality, because people conflate big budget and high production values. Doesn't mean the end product is going to be good. We see overhyped big budget games fail frequently. However, there is a perception and expectation that quality and sales come from putting a lot of resources into the development.

So I agree that not all AAA games are great. However, I disagree that this changes the definition of the phrase. The phrase is about budget and promotion. Quality is assumed but not necessarily realized. Can't change that, just because there are heavily promoted games with huge budgets that end up sucking.