One of the reasons the article cites could also be that the sector has become too speculative. Investors are rushing too fast in and out of tokens, while longer-term investments are lacking. I think platforms like pump.fun could also be related to that problem. The consequence is that some very small tokens get pumped (and dumped after a while) while most others tend to slide lower and lower.
This is another reason why I personally would be very careful with any investment into centralized altcoin projects. Their dependency on fresh capital can mean that they may quit the market at any time or lower the development pace. Of course big projects like ETH and SOL are still well funded, but anything outside the top 20/30 may be dangerous already.
Decentralized open source projects which don't depend on VC funding, like Bitcoin or Monero, aren't affected by this problem. This does not mean they're automatically good investments, but at least there is one substantial risk less.
The problem is most developers aren't building quality projects anymore. At least, not like the early days. Nowadays, it's all about NFTs and worthless "meme" coins that are speculative by design. Around 99% of "meme" coins are simply copies/clones from one another. There's no innovation. Because of this, money from VCs is moving away from the market. The only serious projects I can think about are Bitcoin, Ethereum, Cardano, Polkadot, Polygon, and Solana. The rest are simply pure junk. Even privacy coins are seeing a decline both in terms of development and innovation. The only privacy coin that's still "kicking" is Monero. Coins like Zcash, Dash, and Grin have lost their luster.
I sometimes wish I could go back in time where crypto actually focused on utility rather than speculation. New and exciting projects came up with fresh ideas for the industry. Now with most people joining crypto to turn a profit, don't expect things to improve anytime soon. It's only been 15 years since the crypto industry's inception. I wonder what will happen in the future?