I've been using Restic since 2017 without issue. Tried Kopia for a while, but its backup size ballooned on me, maybe it wasn't quite ready.
It also has extensive support for ignoring stuff and it works very well.
I still use Borg because its policy of expiring older snapshots is more useful for me, but Kopia is extremely solid and I would use it any day if I didn't care that it doesn't actually keep one monthly backup for the last 3 months as Borg does (it decides which older snapshots to keep with another algorithm; it's documented on their website).