I agree that it may be in a bit of trouble, the speed and fees are making it unattractive. I've avoided using it in preference to other side chains for the fees alone. I don't see a real clear replacement right now, SOL has it's issues. I also haven't been a big XRP fan, but it doesn't mean it can't a winner. With the SEC out of the way it might skyrocket, and it might be smart to buy in. I still have to convince myself though and it hasn't happened because I still don't have much.
Cardano could become interesting. I honestly don't have any, there are only so many projects I'm willing to throw money at one time. I wish I had a crystal ball! lol