Yes. Valve (Steam) spent more than a decade building and refining a translation layer called Proton. Nearly 80% of the vast Steam library is now compatible with Linux to the point they are releasing actual Linux consoles (Steam Deck and Steam Machine).

For your regular PC, you can install a gaming-focused distribution like Bazzite to get everything sorted out automatically.

In a word, yes. While Wine has been an option for decades, Valve and Proton have made gaming on Linux mainstream. You can check compatibility reports from https://www.protondb.com/ for whichever games you're interested in.

I haven't had any issues installing AoE Gold under Wine. Furthermore, stuff on Steam is usually trivial to get running (just click and play). With Heroic same goes for stuff on GOG (and presumably Epic as well, IDK). PlayOnLinux and Lutris have good support for games you install from CD (I probably could have used either of them to install AoE Gold, but I've been using wine directly for so long I find it more convenient to do it myself).

Many are playable with Steam on Linux, each game in the store states whether that's supported or not. Even non-supported games allow an override. I've tried that for a few with varying success. Steam has so far refunded purchases that didn't run on Linux. Then there's Lutris which runs many old games fine.

There is a community maintained website for checking game compatibility: https://www.protondb.com/

Having a steam deck, I can say that gaming on linux is totally doable, but you may want to look on protondb to see what is not compatible with your library.

For years now. Look into proton, its built into steam even.

Sure, Valve has done some amazing work in that regard. Most mainstream and older games just work, others require some tinkering.

You can play almost all solo games and most multi-player games depending on anti-cheat

Age of empires will be okay.

There was an article on the front page a few months ago that showed most games performed better on the Steam Deck with Linux than Windows.

recently had need to run a legacy win32 game on linux. the game works fine but the updater is in some windows specific java that i just could not get to work, which is kind of ironic since its the "run anywhere" java that wouldnt work but the C++ game would. anyway -- i run the updater in a windows vm that has shared access to the game files, close the vm then run the game through wine. works.