Steam + Proton works for most games, but there are still rough edges that you need to be prepared to deal with. In my experience, it’s typically older titles and games that use anti-cheat that have the most trouble. Most of the time it just works, I even ran the Battle.net installer as an external Steam game with Proton enabled and was able to play Blizzard titles right away.
The biggest gap IMO is VR. If you have a VR headset that you use on your desktop and it’s important to you, stay on Windows. There is no realistic solution for VR integration in Linux yet. There are ways that you can kinda get something to work with ALVR, but it’s incredibly janky and no dev will support it. There are rumors Steam Link is being ported to Linux, nothing official yet though.
On balance, I’m incredibly happy with Mint since I switched last year. However, I do a decent amount of personal software development, and I’ve used Linux for 2 decades as a professional developer. I wouldn’t say the average Windows gamer would be happy dealing with the rough spots quite yet, but it’s like 95% of the way there these days. Linux has really grown up a lot in the last few years.
You’re conflating “voting for a single-seat position” with any method of vote counting. There’s only ever one winner if there’s one seat, but there are better ways of counting votes than first-past-the-post. At least with ranked-choice, more people are happy with the outcome because the winner might be their second preferred option.