Do you mean that if the issue of high transaction costs is solved, will the ETH price go down?
Maybe this will actually happen, but it is only for a short time when many people feel there is no need to hold ETH as a transaction fee.
However, soon after, as Ethereum's scalability increases, for example 15K tps instead of 15 tps as it is now, activity in the Ethereum network will increase, the number of users in DeFi applications on Ethereum increasing, the need to own and use Ethereum will also increase, Ethereum will continue to be the best blockchain platform, ETH will be the most worthy altcoin. The buying pressure of ETH will be maintained and the price of ETH will continue to soar. Besides, if EIP-1559 is applied, a part of gas will be burned to increase the scarcity, ETH price is even predicted to reach $20K.