Strictly speaking, investing in memes is gambling, you can invest in memes as long as you know what you're doing. it can make you lose but can also help you make huge profits.
You are right, allocating capital is a good thing to do and should not focus your entire investment on meme, just a small amount of money and willing to lose to invest with meme. I invest in memes as entertainment and I don't mind them too much.
Although memes are useless but I believe it will never die, they will always be on the market and they will be more active when the bull season returns, I would rather invest in them when the bull season comes than now.
"Meme" coins are just fun cryptocurrencies you can use without "breaking the bank". While it's possible to profit with these coins during the ups and downs in price, I wouldn't recommend relying on them as a long term investment due to their extremely-unpredictable nature. Most (if not all) of these coins have an exaggerated supply of units in circulation, making it impossible for them to retain a high price for such a long period of time. Garlicoin would be the only exception to this (due to its finite supply), but it hasn't gone to the moon yet because development progress has stalled. People are no longer interested in the cryptocurrency, as they move on to the next big thing.
"Shitcoins", on the other hand, last longer than "meme" coins but they're often a victim of hacks, outages, and other undesired situations. Basically no other cryptocurrency compares to Bitcoin when it comes to achieving decentralization and censorship-resistance. Most of the coins you see now will die, paving the way for other new players to enter the space. As long as you don't put all of your eggs in one basket, there should be nothing to worry about. Just my thoughts