Then why have the mini version if the point was to cut costs(for the custumer), if in the end they will have to buy acessories to actually be able to play every single game the system offers?And no, you dont need a pro controller to have the full experience.I mean, as far as I know, no game requires the pro controller to be played.Nor the NES Joycons.
They won't have to buy the accessories, it is just an OPTION. Most Switch games work perfectly fine with the Pro controller or a third party controller, many of them even better than with joycons.
How many and which Switch games only run with Joycons? Not every Switch owner wants to play 1-2-Switch.
Also Nintendo wants to bring more than one Switch system into a gamer's household. Different form factors can help with that plan. I wouldn't buy a second normal Switch with all the same advantages and disadvantages (and a second dock I don't need) for another €300... but I might buy a €200 Switch mini/lite with better battery life, lighter weight and smaller dimensions for mobile use additional to my standard Switch, which would stay in the dock.
Another mistake that gamers make is to think that having more options is always better.Ill quote Delio because he basically encaptures what I think about this subject:
"An improved Switch is the most reasonable option.
Price wise, if the improved version is more expensive, then, by comparison, the Switch OG model would look cheaper. And with time, with lowering price you'd eventually reach another audience without the need to compromise your future.
An improved version would, in theory, allow for more multiplats and ports to arrive to the system.
A mini version that makes it a handheld is the same as rejecting what make the Switch a success, it would also make it seem like an inferior product. Why should people opt for a mini version when they can't get the best experience on the original Switch? The potential of a such a model would be limited by default.
Not to mention how certain games would be affected by the fact you wouldn't be able to detach the controllers.
One of the main reasons that made Wii U fail was poor comunication.
Having the communicate that you have two devices that do not work the same would sound messy and awkward. Not the best thing when you want to market multiple products."
One thing that I would add is that it makes more sense to launch a Switch Pro(that just bumps things like battery life, screen resolution and so on) after the base Switch has already been discounted, so you would have 200 or 250 dollars version and a 300 or 350 dollars version.And for that, the base version still needs to be discounted.So thats why I dont think this revision is comming in 2019, even if I do believe it will happen(A Pro version, not a mini one)
For your question of how many games need the joycons, out of the top of my head I know that 1-2 Switch, Super Mario Party requires joy cons.Pretty sure there are more games.But not only that, but there are also games that have exclusive features that revolves around the functionalities of the Joycons, such as Mario Tennis with its motion controls, Senran Kagura(For whoever likes those games lol) and probably many more in the future.Not to mention that you lose alot of value not having them detachable, since you basically come with a second controller out of the box that you dont have to pay extra to have.