There is no tit for tat in politics. It's all tit. You think Mitch is retaliating against Harry's filibuster move, but I think Harry was retaliating against Mitch's obstruction. The (unwritten) rule before 2009 was that the minority would not use the filibuster indiscriminately against lower court judges. Mitch changed the unwritten rule, so Harry changed the written rule. Tit for tat. Obviously, Harry's tit didn't work to restore comity; Mitch (and you) say it was actually a tat worthy of its own retaliatory tit.

Many senators want the filibuster to remain a viable tool for preventing a tyranny of the majority. If Biden wins and the Dems take the Senate, I believe Sen. Merkley will get his wish. They may have to go a step farther and bring back the one-track rule. Hopefully, enough Dems understand that they lost the White House in 2016 because Mitch was so good at making his obstruction look like Obama's fecklessness. I don't believe Schumer would have the votes to get rid of the filibuster entirely.

A filibuster should come at a price worth paying only for serious objections on serious matters. It is the majority's job to make that change. There will be a new Congress in 2021, and whichever party is in charge should make those changes for the good of the country. Mitch has had his chance to "get even" with Harry, if that's what you think he was doing and was right to do. Now it's time to do something about Congress's well-deserved dismal approval rating.