I don't have much experience in group theory beyond knowing what a finite simple group is, as well as the other basic parts of the topic, so far as I can tell, so if the actual answer is too complex to be summarised clearly then just say and I'll understand that.
So far as I can tell the classification of finite simple groups states that if you were to find a finite simple group of order n, it would either belong to one of the four families or is one of the 26 sporadic simple groups.
Is it proven then that there are no more possible families of finite simple groups, so incredibly large that we couldn't find them with computation?
Is it proven that all of the sporadic simple groups smaller than the monster have been found, and that there cannot be any greater ones?
If the answer is yes for either one or both of those questions, then is there any way to summarise why in fairly simple terms?
If the answer is no for either then what is the mathematical community's opinion on that?