He has a very limited view of what is required of software.
The problem is that he's not entirely wrong. The JavaScript-ification of everything is kind of a problem. Electron apps everywhere is an issue.
But a lot of issues are also just trying to deal with bad actors. Doing authentication or authorization wrong can have real consequences. And it is incredibly difficult. Because security is in opposition to access. And trying to make security invisible is even more difficult.
What is a game save file if not persisted state?
Compared to if you run a cloud storage company, a corrupted file might annoy a user that pays $1m every month, to store data that they themselves make money on, etc.
The stakes for a game save are a lot lower.