As cheap as gas fees are on the ethereum network, in my opinion it is expensive, because other networks such as Binance Smart Chain, Solana and Tron are much cheaper. Currently, because the traffic is low, that's what causes the ethereum gas fee to go down, but if traffic goes up we will also see the gas fee going up.
That's right, when you want to make transactions between exchanges it is better to use the three networks you mentioned because so far Tron, BNB and Solana have very cheap network transactions. Instead of using the Ethereum network which has quite expensive fees.