capitalism vs socialism vs communism

i keep getting into discussions with people who don’t see communism as achievable or “the right thing” for our current society (which i partly agree with, as i don’t believe we as a society are READY for such a revolution yet) but they keep bringing up this thing that i can only describe as “socialistic capitalism”??? no clue. they want for society to be more socialist but keep some capitalistic values because they think full on communism wouldn’t work. but from my understanding socialism is just the step in between capitalism and communism, it’s meant to make communism more achievable. so i guess my question is: theoretically once we reach a stable state of socialism, what’s stopping people from viewing communism in a similar manner to how they view socialism now? do they think we should stop at socialism because they’re scared it would be too “radical” to go further? or because they’re conditioned to live within capitalism and are scared of change?