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?
No, Bitcoin receive that kind of criticism too when Ethereum was introduced and hype but still no one can beat Bitcoin despite all the FUD circulating on it. This same scenarion on Ethereum which a lot of competitors' blockchain is lurking to steal its top spot but Ethereum is still a solid project due to its real decentralized nature so even with the cons that you mention, Many investors still trust this coin due to its well-known brand. The only that will bring down Ethereum is a serious security breach that will cause a loss of funds like what happened to their DAO before but this scenario has a very low chance to occur.