Initial benchmarks show better performance than btrfs (at least for some workloads), but more importanty, I like that it offers tiered/cache storage - so you can use a fast and small drive (NVMe) to speed up a slow and bigger drive (HDD). You can do that with ZFS as well of course, but it doesn't have the massive RAM requirements. Also it's much more easier to set up and configure in comparison.
BTRFS is honestly really great and has been for the last few years. Dont take the word of random people on the interwebs, check out some modern sources of info on the subject. Some people love to complain about RAID5/6 but if you use BTRFS the BTRFS way then it is solid.
With that said, if you dont need snapshots, drive mirroring, sub volumes, bit rot protection etc then EXT4 is hard to beat for reliability.
Its got a closer feature set to ZFS (tiered storage is going to be huge for me personally), but a much friendlier license. ZFS's licensing drama solidly convinced me not to touch it with a ten meter pole. BTRFS isn't bad as well, I currently use it, but tiered storage is excellent. Was the only reason I used to consider ZFS, but becachefs is getting to have my cake and eat it too.