factorio, stardew valley, undertale, don’t starve, super hot, goat simulator, cup head, rocket league, kerbal space program and so many others.
heck steam, Sony and Microsoft are competing to distribute this IP and open it up across platforms and it’s never been better.
Some of the examples you give also had quite a history of a backing in some form, which is a totally different animal compared to a "I wanna make a game!" indie developer today with zero network and zero funding.
There was a golden age of indie gaming 5-10 years ago, but it does feel like that has passed somewhat.
Since then the market has gotten way more saturated. Games have gotten way higher demands on all three fronts of polish (gameplay, audio, visual). If not a roguelike / player-generated content game / simple loop, lack of content is even more killer (which is why so many indies are either arcade, sims or roguelikes, compared to AAA games). Even several of the titles mentioned in the comments would rather come out with sequels building upon their success or games highly similar to what they made before, than experiment. Most indies I checked who deviated too far from their big hit (devs from Castle Crashers, Deathroad to Canada, Binding of Isaac) had nowhere near the same level of success. Not too bad considering they can coast by just off of their main hit's success, but it does illustrate the lack of moderate success.
Or you can try make a big hit with a meme game (anime optional) and be forgotten in the next 2-5 years.
EA, DICE, Take Two, Ubisoft, Bioware, Konami, even the once vaunted CDProjekt Red's reputations are in tatters (of course, they still sell tons of games). Gamers are tired of copy and paste money grabs, full of bugs on launch and overhyped to the moon.
The accessibility of game development tools to almost anyone globally, the pandemic, and the relative ease of digital distribution is a boon to indie game makers (Steam, Epic, Itch, GOG, Indiegala....).
Valheim, Among Us, Project Zomboid (launched 2013, becoming much more popular recently), Escape from Tarkov are all examples of indie games doing well. Check out /r/patientgamers and related subs and you'll see more examples.
If this was actually true, the companies you mentioned wouldn't be selling a ton of games and gambling gimmicks didn't need to get banned for companies to stop putting them in their games. In reality, successful companies are better off iterating on their existing games and systems a few times until the sales die down, then maybe release a few later for nostalgia and move on. It's much less effort, less risky, and it plays better into the expectations most people have.
This has been going on for well over a decade. It's not like people haven't had the chance to see the trends yet.
That being said, supergiant is a rare gem. Shows how effective lean organizations with narrow concerns can be without needing to be abusive.