My game started crashing every 1-5 turns in April, and it had been fine before. The crashes made Civ unplayable.
The system is a 2020 HP Omen laptop with Ryzen 7 4800H, GF GTX 1660Ti, 16GB 3200 RAM, Win10. No mods. Launcher bypassed. Latest drivers and updates to everything in the system. All DLCs and expansions for Civ installed.
The crashing issue might be linked to the infamous windows KB5001330 update from early April. It is widely reported to cause FPS drops and game crashes in many games. Microsoft implemented some hotfix for it at the end of April, but I see people are still reporting issues after the hotfix. Uninstalling KB5001330 is recommended to restore game performance.
Initially I could not uninstall the update. I could see it on the list of recent updates, but it was not displayed in the menu that allows you to uninstall updates. However, after I uninstalled all the updates that were installed after the 1330 update and restarted my system, it became possible to uninstall 1330, too.
I do not have time at the moment to test whether this solved the crash issue, but I will report back here within the next few days.
Edit: I just managed to play ca. 10 turns without a crash, the best result in several weeks. So I think I can tentatively say uninstalling the KB5001330 Windows update did the trick.
Edit 2: I tired playing more, and again I ran into crashes. Apparently the 1330 update solution was either false or temporary. On page 6 of this thread I describe what I did next to fix the crash issue, with good results.