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.
As I said above, and you can check the history, in recent years, ETH has always given a much higher ROI than bitcoin, and if you also have faith in ETH it is also a good choice along with bitcoin. Nowadays, newbies like to invest in altcoins for the same reason, they like high returns and bitcoin no longer fulfills that requirement. But other altcoins are extremely risky, and only ETH is a safer choice, but the returns are not bad either.
Bitcoin fanatics have always considered ETH to be shitcoin, but looking at what it has done and achieved, those who invested in ETH early were just as successful as those who invested in bitcoin early.