Small block size is the main reason why Ethereum has very high gas fees.

Smaller block sizes often lead to network congestion, and knowing how popular Ethereum is, many transactions are waiting to be confirmed. Because of this, it often leads to higher transaction fees because people want to get their transaction confirmed as quickly as possible, and they're willing to pay higher fees for it. This is the reason why Ethereum has high gas fees currently.

TBH, I don't know how Ethereum will solve this high gas fees problem, and to my surprise, there are still many new projects that are being created under Ethereum, and I don't know the reason why.