“Just” like with GDPR, “just” follow the rules for personal data management. In reality, compliance stuff like that is expensive to implement.

So if you are going to require it, don’t pretend it is without cost. Which is exactly what you seem to be doing.

Which is true and all. For many things.

But if I just want to decode some JSON for a computer game, it is nice to just be able to do it on a website, with no need to install anything.

Though not having to download and install a random program from the Internet, with full access to your hard disk, is often nice. When running in the browser, it is automatically sandboxed hard.

Why do you think it is based on manual input? It would make a lot more sense if the Steam software detected the framerate automatically while you are playing.