Both Fedora and openSUSE default to Btrfs. That's all the praise it needs really.
With Bcachefs still being relatively immature and the situation surrounding (Open)ZFS unchanged, Btrfs is the only CoW-viable option we got. So people will definitely find it, if they need it. Which is where the actual issue is; why would someone for which ext4 has worked splendidly so far, even consider switching? It's the age-old discussion in which peeps simply like to stick to what already works.
Tbh, if only Debian would default to Btrfs, we wouldn't be having this conversation.