I hold many old coins
Doge
Reddcoin
Xvg
I hold these coins because of their history. Past performance and utility with great community support. Doge enjoys huge community support.
Those are very good coins that have stood the test of time. While most people are focused on the "new kid on the block", tried-and-tested blockchain networks like the ones mentioned earlier are a much safer alternative for decentralized finance (except for Verge/XVG). Personally, I'm a fan of Dogecoin due to its blazing fast speeds and inexpensive price across the market. Anyone that's willing to experiment with crypto can resort to Dogecoin because of this. Of course, development has stalled ever since its developers abandoned it some time ago. But with a vibrant community supporting it every way, it could survive for a very long time.
Reddcoin is also a good-old coin that's active in development after all these years. It focuses on social media payments at a fraction of the cost of traditional cryptocurrencies like Bitcoin or Ethereum. With years of development and innovation, I think Reddcoin is a very undervalued cryptocurrency these days. Another old coin I'd like to mention that's not on the list is Namecoin. It was the first cryptocurrency to make use of a decentralized DNS in order to make the web a better place. Before Ethereum's "ENS" came into inception, Namecoin pioneered the concept of the "decentralized web". Decentralized domain names are proven to be censorship-resistant, allowing websites to remain impervious to government or third-party intervention. While trading activity for NMC is quite low these days, the core Blockchain network is still alive and running after all these years.
Nonetheless, it's good to "hodl" old coins since they have years of experience in the crypto/Blockchain industry. That's not the case with new coins on the market full of experimental features that could threaten the security and reliability of the underlying blockchain network. By choosing old coins like Peercoin, Blackcoin, Monero, Litecoin, Dogecoin, Namecoin, and Reddcoin, you'll feel confident that your funds are safe against external attacks. Of course, many of these coins are undervalued in terms of Fiat. But, what matters is utility above all else. Just my thoughts