I don't really know for Altcoins, if the number given above is correct, then they (altcoins) make up '14028' of the crypto listed on CMC, that means they are so much, and quite a lot of them do not have use cases, some are pump and dump coins and others are basically just controlled by scammers, thus many of them would crash, dump and disappear, the thing is just that, it's somewhat impossible to understand what will happen with altcoins.

Having said that, Bitcoin is so unique, and it's adoption has gone a step further since the pandemic 'shed its milk teeth', I sincerely doubt Bitcoin will experience another massive plunge/crash in price, there would definitely be correction periods, but a massive crash may not be on the cards for Bitcoin anymore, the network has prolly outgrown that.