I've been playing since alpha. I bought it the first day it was on sale. I bought it on steam a second time. When the expansions came out they gave me them on the first purchase. I will do a career run every now and then but most of my games are sandbox games with huge multi launch space stations.
I've been playing this go round for a about three months and when I get bored I'll park it on a drive for several months then I'm back at it.
I still get a kick out of manual(No Mech Jeb) mun landing and returns.
KSP 2 is a little better than its first release. I still main play KSP 1 in sandbox mode. If you have a problem with parts counts get a part fusion mod and combine parts to increase your FPS.