It's only fitting that an undemocratic and arbitrary rule designed to impede the will of the majority of legislators is used to help ensure the continuance of undemocratic and arbitrary rules designed to impede the will of the majority of voters.
It's interesting though that Manchin and Sinema only believe this needs to be at the federal government level but that there is no need for a filibuster for state governments.
It's also interesting how in all the Republican majority states where none of these governments have the filibuster that these Republicans aren't rushing to bring them in in order to defend minority interests. The only thing that is similar to the filibuster at the state level that I'm aware of is states that require a supermajority to raise taxes.