You know, every 6 months or so I get a sudden hankering to play Portal or something and start down this rabbit hole. Based on your prompt, I had another look today.
So I went and downloaded this "whisky" thing. From their website: "Experience the latest titles effortlessly with Whisky!". OK. Installed.
I open it and I see a window with "bottle configuration" (wtf is a bottle?), an "open c: drive" button (???), "SteamCMD" whatever that is, "winetricks" (??) and a "run.." button which opens a file from finder (??). I have absolutely no idea what any of this is or how to proceed.
Confronted with this and the prospect of hours of research and messing around I decide I don't need to play anything all that much really.
UPDATE - ok, I decided to actually try and get it working and it's not that bad. Follow this video, basically: https://www.youtube.com/watch?v=xowJ3b-pt-U
And protip, set your system audio to 44.1khz. Cool. Portal.
I maintain the user onboarding could be MUCH more friendly.