I’ve been loving it honestly, I used to mess up my systems pretty often in a way that upgrading to new releases had to be done from the command line because of random repositories I added, so things felt unstable.
Immutable systems on the other hand are dumbass (me) proof and I can still do what I used to do with those repos in safe environments or Flatpak now that it has become so ubiquitous for packaging.
Immutability is not a must, even though I really like the philosophy, in fact, if you’re comfortable with what you have, you might be fine just converting over your current OS to btrfs.

Good luck, whichever option you try!