I see Blockchair.com is winning the poll race , but if we are to introduce mempool to the race I honestly don't see Blockchair winning by the huge margin it's enjoying as am aware most of us today use mempool for the extra technical and visual details available to Bitcoin enthusiasts.
I used to be a big fan of Blockchair.com explorer until a day they deployed a new user interface. It happened a long time ago, like years, but with that upgrade, they no longer display a full address, only display a few first and few last characters of a address, that makes it is harder to find an address with their explorer.I don't know how others feel with that upgrade but after that, I barely use Blockchair.com
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OP, humble request add mempool to the pool if possible 
It is a great request because as a non custodial Bitcoin wallet users, mempool information is what we take a look at before broadcasting our transaction.