There's a load of discussion around this down the years. Gamepass and MS are usually credited as one of the better paying services for devs. I can hardly think of an indie Xbox title that isn't on windows (Steam)... and TBH I have read far more devs raising issues with how Steam fails to bring quality indie titles out against the backdrop of immense amounts of utter tosh. Great, great games with less than ten reviews out there. If the hive mind and algorithym don't go for it, it's a real struggle for them. Even then, with Steam's cut, the uncertainty if you're selling a hundred, or ten thousand, and the wild popularity of key resellers that break into the dev's profits even more, it's a hair raising experience for someone to go it alone. Most devs end up giving away keys for pennies to bundles and so on. And then there's rampant steam piracy.
In that way, you're right to be concerned. Getting onto console historically offered devs a more favourable, less saturated market. And getting onto XBox isn't as crazy as PS. If you are lucky, PS will offer you an exclusive deal... I'm not a fan of that as a PC gamer, for sure. Apple have done the same thing... the dev may have no choice but to take a solid deal, but you do wonder how they will fair having sacrificed exposure, which is a huge, huge determining factor in sustained sales, and who gets a viable business going forward. Realistically, Switch is often the best market to get onto. I've watched a few games now sink without trace on Steam, only to later find popularity on Switch, which then leads to a massive increase in exposure and social media content, which then drives the sort of sales on Steam I'd have expected in the first place.
A really small developer who gets on Gamepass (or a deal from Epic, or PS, or Apple Arcade) - and there's been quite a few now - gets that transformative deal that offers them stability going forward. They know it will further drive sales when the game is withdrawn from the service.
Does it stop people checking out Indie stuff and making purchases? I'm not sure. What I've heard anecdotally is promising. People who wouldn't have checked out games like Carto, or Spiritfarer, randomly do, and enjoy the hell out of it. That's going to be good for the indie sector as a whole. Otherwise, they are largely in the lap of the very popular streamers... and that's not great, games good to watch, are not always that clever to play, multiplayer is one thing, but it's been very hard for devs of single player games. And that Steam / Youtube / social media hive mind / group think can be petty, unreasonable, cruel, abusive, absurd, arbitrary, immature, political, easily manipulated ...sometimes to devestating effect. There's a really strong argument that MS and others are very welcome protectors against that hive mind taking over completely.
