I can only speak from experience here. There are some times I may get a bit tired after a shot but otherwise I haven't really had side fx that I can tell.
That said, just being on it, does make you susceptible to other things. In the six years or so I've been on it I got shingles, mono, and covid. Could be a coincidence.
But I suspect my lowered immune system made me susceptible. With mono, for example, I'd already had it once, so it was weird to get it.
Anyway, you do have to watch out for some serious possible side fx, as with all biologics, but, all that being said, the benefits, for me, seem to outweigh the drawbacks.