Not only XRP, but it can also be seen that besides ethereum, the remaining long-standing altcoins do not have a bright future. They can barely keep up with new projects, and that is why there is always an elimination in the altcoin market. In my opinion, if you want to invest in altcoins, you should only trust ethereum, all other altcoins should not be long term investments. Even if XRP wins the case, I still doubt its future, today we have too many altcoins with utility outperforming XRP.
In Alts category apart from Ethereum there is no single coin that is able to retain his position. Since I started following crypto in 2017 I am seeing Ethereum at number 2. Lot many coins make it to top 10 but none was able to retain that spot over time. Ethereum is good choice in alt but it's price is attached with bitcoin, so why not invest in bitcoin directly as Alts will join the party only if bitcoin goes up.
I remember XRP replacing ETH before at the top 2 position but that was the time where XRP still have no issue with SEC. Now, they are still hanging around and just waiting for the decision of the SEC, for me XRP is still a good one because they are able to get more investors and business partners even if they are centralized. Doing DCA with XRP can be good but its not a guaranteed return since they are still facing problem with SEC.