That could happen, but if Republicans are going to be insistent on blocking every normal bill Democrats propose, sooner or later Manchin and Senema will realize they need to vote to end or modify the filibuster. If not, we would have a repeat of the Obama administration when the Republicans blocked everything.

A proposal they both might go for would be to modify the filibuster so it takes 60 votes the first day, 55 the second, and 50 votes the third day to reach cloture. This leaves plenty of time for debate on a bill, while preserving majority rule. Interesting point: There is nothing about the filibuster or a 60 vote requirement in the constitution. The founders wrote it as a simple majority, with the VP casting a tie-breaker vote. If it ever got to the Supreme Court, they could easily decide it's unconstitutional.