CAT is kinda a weak attempting at "cashing in" (harharh) at Dogecoin popularity lately. The only reason I see it even used is by people who wished they jumped on the dogecoin train early.

Plus the early miner advantage is much higher with Doge and is based on a (I hate to say it) fresher meme than lolcats. Catcoin popularity is probably not going to be longlived. Really most altcoins don't really have much purpose over BTC, and the fact Dogecoin got popular at all is that it didn't take itself lightly. If the competition does however, they're kinda losing the point why Dogecoin got popular in the first place.

This will be a unpopular opinion but if someone asks me to buy a specfic coin for serious longterm investment, I just point at BTC. The rest is for fun, but none of the altcoin offers anything really other than being more "fair" at mining (which actually makes said altcoin more vulnurable to 51% attacks). Altcoins can be a fun investment for those who find that BTC have turned boring volatility wise though.