Even without any utility, they are performing better than bitcoin. As an investor, will you not consider returns while making a choice between which crypto to invest ? The fact that they are rising so fast in comparison to bitcoin is an indication that there is more demand for mem coins in comparison to bitcoin.
Firstly, they are not performing better than Bitcoin.
Secondly, I consider returns as an investor, but top of my list is asset security, I wouldn't comfortably hold a coin a thojt utility for years. I would only trade them over a short period of time.
Crypto world is very unpredictable. I would not be surprised if some new altcoin replaces bitcoin as the number one coin in terms of market cap in future.
They would need to last long enough to attempt that.