Don’t install the 5.0 or later version of Wine. I fixed the problem below by going back to 4.19/.
My launcher was having trouble after the most recent patch, hanging on the gray screen that looks like the new trailer. I forgot accounts, cleared the cache, reinstalled the launcher, but nothing worked.
So I tried reinstalling Wine. It needed Xquartz first, so I did that. Now when I start the launcher it says it’s reinstalling wine, the progress bar goes almost all the way to the top, but not quite, then it says “wine up to date” but still doesn’t get to the top, and it starts downloading Wine and redoing everything again.