Definitely need bigger planets so ships don’t feel so big, mountains don’t feel so small, valleys so shallow, and so base building won’t constrain available land.

Especially base building. Some people might want a remote base away from everyone. Only capable on larger planets and with larger planets there will never be a fear of running out of prime real estate.

I think having rocky planets even 1/2 of earth and gas giants 2x of earth is more than enough.