High gas fees, reduced popularity of DEFI, rapid decline of TVL on the chain, distrust of ETH2.0, criticism from miners, and restrictions on participants by the POS mechanism. Will the challenges of new technologies and new public chains cause ETH to decline rapidly?
This has become an issue for many years after the last Bullrun 2016-2017 and yet, ETH is still alive and kicking, in fact, it is still a highly recommended altcoin for investment.
You can't assume that thing OP as people had never lost their hand from investing ETH despite of its high gas fee. Even to see there are more new projects that are coming they are way far in terms of market appreciation and profitability. And aside from that, ETH has a big role in the market making this more important than these new projects.