@freemo I have never used LVM before. I though Btrfs can handle drive changes pretty well. But it looks like LVM takes it to another level, in terms of disk management.
For now I only have 1 disk with LVM+LUKS+Brtfs, but in the future I do have a plan to add another disk to saturate my nuc. I'll see how lvm helps at that time.
@skyblond i only use the basic functions of BTRFS, snapshots, backup, and copy-on-write.. the other stuff is a bit buggy and as you point out not as powerful as LVM anyway. Also you are likely going to need different formats on different partitions so you will need LVM anyway.