On one end(Solasta): You have a "full" game experience, but there's more that can be had. You don't have to buy ALL of the expansion packs, unless there's something you want in each, but each expansion comes with adventures to go on as well as an extra class and/or race or two. Granted, this also has built in tools to make your own adventures as well.

On the other, you have BG3(at least according to this image), where you get the whole kit and kaboodle up front. Pay once, play to your heart's content. Granted, TMI, this lacks and will continue to lack tools for making your own adventures.

Then you have the golden years. You get one full game up front. Feature complete, full story arc for each race. Then later down the line, an expansion comes along that builds on it, using the engine from before(maybe with improvements), extra units, maybe a new race, and a new story line for each current race. IIRC, these older games included tools for making maps, but not quite full campaigns, but my memory is a bit fuzzy on that.

There's also a game like Elite Dangerous. IMHO, it breaks a few rules. You have to pay up front, although only $20 for standard + $30 for odyssey, but you own it from then on. No monthly fees, or anything. Maybe the next huge release in 5 years will be another $20-$30. However, it's an online game, going 24/7/365(minus a weekly reboot). They have to pay for the servers /SOMEHOW/. Only an idiot would buy the game more than once, so (try to) sell you paint jobs for everything, and gear for FPS mode, among a few other trinkets. I do appreciate how it's 100% cosmetic only. Zero ptw whatsoever. Again, IMHO, this is the least bad way to do this.

Then there's Eve Online. Free to play, but you're limited in what you can use. Pay for a sub to get access to use anything(must still have character skill and buy it with in game money) and you can, in a round about way but a supported by the devs way, pay that subscription using in game money. They also have cosmetics. The downside, you can pay real money(or trade in game money with another player for this currency) to get a skill point injection kit* or open up to train on a second(maybe third?) character at the same time on the same account. The skill point injections aren't 1 hour xp boosts, and they're not instant lvl 60 potions, the more skill points your character has, the less you get from injecting. You don't buy the injection, you buy the syringe, suck the sp out, and sell on the market. Those sp came from another player, and you don't have to pay premium currency for it, can use the in game stuff. Again, it could be better, but it's better than many others.

For the most part, micro-transactions are a cancer on the gaming world, but due to human greed, I don't see them going away in my lifetime. Now that most everything is being "published" digitally, we don't have any actual scarcity of the games themselves. There's no threat of not being able to get the game on launch, and having to wait months for a reprint missing having it for your birthday lan party. Early access is not a terrible thing, it should just be called what it is, THE ALPHA/BETA program, and should not be full price, unless you are getting some big rewards on/before launch, and those need to be properly disclosed ahead of time. Larian could have done better on this, but they're at least not StarCitizen.