I think the main solution is to have an easy way of searching for existing communities before deciding to make you own. browse.feddit.de seems to be a good step in that direction to me.

"We're offline working to restore access to subreddits that went private for some reason" - Reddit, probably later today

After just getting started learning to do my own car maintenance, definitely the subreddit dedicated to my model of car

FWIW this might be related to a Cloudfare outage: https://www.cloudflarestatus.com/

No idea honestly. My best guess would be that browse.feddit.de hasn't cached those communities yet if you just recently created them. There's options to turn on/off different instances in the sidebar, and it looks like feddit.de is on by default.

People have been joking lately about productivity suddenly increasing as a result of the Reddit blackout, but honestly? That loss of information is probably going to result in a loss of productivity in some cases.

Because yeah, in the nightmare scenario where both Reddit and Stack Overflow were to disappear, a lot of programmers would be at a complete loss.