1080p is not so good on Youtube, but my computer crashes when processing at 4K (I'm using Davinci Resolve). Is 1440p a preferable resolution? Why is it not so popular?

I think 1080 works well, also on YT.
But you might get better results at 2.7K
I sue that a lot (1440)

2.7k Appears to be the sweet spot for most drones.

1080 is good enough for YouTube, most people view videos with a 1080p screen.

My computer is also not good at handling high-res footage when editing on TunesKit AceMovi, so 1080 is the best for sharing and viewing.

what issues are you having with 4k on your computer using dr?  when you say "crash" does that mean when you try to render?

The Saint Posted at 1-18 18:10
what issues are you having with 4k on your computer using dr?  when you say "crash" does that mean when you try to render?

It crashes during render. Probably my RAM is insufficient because Davinci Resolve's minimum requirement is 16 GB. Meanwhile, mine is 8.

MuhlisG Posted at 1-19 08:26
It crashes during render. Probably my RAM is insufficient because Davinci Resolve's minimum requirement is 16 GB. Meanwhile, mine is 8.

i don't believe that is the issue.  try one of these:

https://www.youtube.com/results?search_query=davinci+resolve+render+4k+crash