I mostly use the latest Versions (I use 4.4 mostly and if something doesn’t work I try it in 4.3), but not because ‘they are better’, just trying to keep up with what changes.
I rarely Delete Versions (only Subversions) and at the moment I have about 17 different Versions lying around, so it’s not so much updating for me, as adding a new Version each time.
It is, like Omar said, not a big deal whether you update or not.
In my experience, it is usually not a problem to open files, made in an earlier Version, with a more recent Blender. You can also, just to be sure, add the Version number to the name of your .blend files, so you’ll always know which Version definitely works for each file.
