I was talking about online multiplayer against (untrusted) strangers. I should have been clearer about the online aspect.

In online PC gaming, cheating is a real problem, as people are able to modify the game to their advantage. This is next to impossible on modern consoles, and cheating is much less of a problem there.

I don't begrudge anyone who wants to opt-in to a designated cheat-based multiplayer session, of course, but it can be a real problem for 'ordinary' gamers.

That is a problem with the games and with the industry, not with the PC as a platform. Heck, if the console companies had invested in properly secure cheat-preventing solutions (i.e. better network protocols that don't leak info, cheat detection by packet analysis, better replay analysis and banning tools for server admins, decentralized trust/authentication systems, etc) then likely those could have been deployed on other platforms. It seems that nobody has been investing any money in that though, everything has instead been invested in making sure that the hardware is a walled garden. This approach might work temporarily for the individual manufacturer of a single console until it gets cracked and they have to manufacture a new one. But as you can see, it doesn't scale past that.