- when you change them for political advantage, you give your opponents a rationale to do the same. It's called a "race to the bottom".
- often you can't predict the result.
I gather the Democrats will likely do away with the filibuster in the Senate if they gain a solid majority. I'm not clear that the conservative Dem senators would go along if the votes of Manchin and Sinema were needed.
They may try to do something with the structure of the judiciary, given the games McConnell et. al. have played over the last 5 years.
I'd rather see the Dems work harder, donate more, and win longer and bigger than take the political risks of changing rules.
But then, I'm a rather conservative liberal Democrat I suppose.