I've been running a small game dev studio for ~20 years, and the one change I think must be made, is to ban the usage of "buy" when it comes to games. Games are licensed, not bought, and that should be crystal clear to those who are paying.
Most of the games people play runs using proprietary software and/or licenses, and often on very specific hardware, with game features that makes sense for the amount of players the game has. Requiring that people should be able to play such games if the company stops running it would completely change and limit how games are developed, and in many cases require a completely different version of the game to be co-developed in case people stop playing it. It would with 100 % certainty result in slower development, fewer games, and worse games.
I do of course think that developers should try to make games playable without the company being involved, within reason. Some games that do not have licensing issues or complicated server backends as a requirement could be made available without too much work. But for things like e.g. MMORPGs it's nearly impossible. If your ever developed bigger software systems you know how many moving parts are involved, so just imagine the difficulty of making it work on consumer machines...