The advantage of memecoins existance in the market is
It could able to create awareness to those people who doesn't know about crypto and they will be aware that memecoin and other altcoins exist.
Some of my friends got to know crypto because of the hype of meme coins. Meme coins usually have a strong community and therefore they also diligently promote them on social media. Compared to cryptos like Bitcoin or BNB which have many technical aspects, meme coins only offer to buy and wait for the price to rise and make a profit. Because of that, people became interested and after that they became aware of other cryptocurrencies that had more real use cases than meme coins.