EndeavourOS is basically Arch with a nice installer and a few extra QoL packages while Manjaro manages their own repositories and adds things like mhwd that change system management to be a little different than Arch.

I much prefer Endeavour since I already do everything from the command line anyway. Also, while most info about Arch applies to Manjaro it doesn’t always and I found that very annoying when trying to troubleshoot.

I’ve also installed Arch a few times and it went fine, but the Endeavour installer is a much nicer experience.