When I compare BTC mempool count and ETH transaction queues, ETH queues are much larger. I would appreciate explanations why it is so.
*BTC mempool count
*ETH transaction queue
The ethereum chain has a far higher number of transactions than the BTC chain. This is mostly due to ethereum's faster block time, and the presence of many thousand smart contracts on ethereum, which all contribute to more transactions.
In the comments, it seems like you are comparing the transaction volume charts to the trade volume charts.
Trading of BTC and ETH happens largely on exchanges. These exchanges have trading engines that execute all trades within the exchange itself, and not on the blockchains. That is to say, if User A sells to User B, there is no corresponding blockchain transaction transferring those coins. Instead, both users have accounts on the exchange which are debited and credited. A blockchain transfer only takes place during deposits and withdrawals.
Through this process, many thousands of trades can take place without ever reflecting on the blockchain. However, interactions with smart contracts must happen on the blockchain, and contribute towards the total transaction volume.