Memecoins are also alts.
Let's not be too sentimal, you actually judging from a deductive aspect, memecoins are known to be hirely misleading but out of them all, few have been proven to be successful, many investors has gotten enough profits risking it in these memecoins and earned a lot more than they have in any Altcoin. It is advisable when dealing with memecoins, one should invest little, something we can do without even if the price drops to zero, it wouldn't affect our standards of living, we only need to apply caution when dealing with them and not totally avoiding them, it's a personal decision aswell.
Well, because they're successful they've become relevant. But if it's not for their success and not for the start of dogecoin then most of them aren't really going to be as good what they are right now. Those that have been developing memecoins, they're just going to repeat the cycle and will continue to earn from this hype and market.