I, on the other hand, find Btrfs to be the file system of the present and hope it will be improved or a better solution with equal or better functionality will be found. It is a modern file system, like OpenZFS and APFS, fully supported and integrated in Linux. It still unfortunately has bugs in specific RAID configurations, limiting its use in certain contexts, but otherwise it is okay. By now snapshots, sending and receiving data, copy on write and transparent compression are what should be the norm. Integrated encryption is still missing, for example, and I hope it will be added soon. Ext4 though reliable and performant is still yet another evolution of an outdated concept.