The problem with old coins is that they are not having flow of usd like before and it's discouraging because people that used to see potential in old coins to always rise are not seeing that tradition again and I think a time will come when old coins will be there because it's only old money that is circulating within it, there is no new money coming.
The only coin that is old and doing well is Bitcoin, it doesn't need any Kol to shill, doesn't need anyone to make them do something but people that believe will always believe and new money will surely comes in.
Not all of the old coins have low liquidity. Most of them though like EOS, XEM, NEM, IOTA and others have already dropped from the top all the way to around top 100, but there are some who stood the test of time, and still at the top.
Coins like Ethereum, Litecoin, Cardano, DOGE, XRP, and maybe we can include BNB on the list as well but the first 5 that I said are what I like to term as "established coins" especially Ethereum that has been in the industry for a very long time and has been the 2nd in terms of market cap.
Right now, where Spot ETFs are being accepted, the top coins that these companies will use are those old ones such as ETH (accepted already), XRP, LTC and even DOGE as well. SOL is the only one that I saw that's an early coin, but companies see potential of the project hence, using it to apply for a Spot ETF.