I starting asking myself this when I remembered a part of a DIC cartoon where Goombas are treated as savage animals and appear in cages. I could forgive this, because these cartoons are not canon, and even if they are, there are moments were the Goombas take photos and other things.
Then I remembered a citation of Super Mario Odyssey who referred to some Goombas as "wild Goombas".
So I started thinking how they are not seen to talk, and sometimes not seen to have a society, indicating they are just like savage animals. They could be just like trained animals of the Koopa troop, just like Chomp Chomps. But this is contradicted in spin-offs, like Paper Mario and Mario & Luigi, but these might not be canon.
Is there any canon evidence to suggest that Goombas possess human-level intelligence, or wild animal level intelligence? Is it possible that Yoshi eats them even though they have human sapience? He eats Koopa Troopas, who are clearly sapient.