Feinstein, Burr, and others like them haven't been champions of mass surveillance powers extensions for the past 20 years out of "ignorance". They know exactly what they're doing.
I still remember a video from the Senate floor showing how ruthlessly and in bad faith Feinstein argued FOR FISA 702 extension back in 2012 using lazy fearmongering about terrorists - the same kind of bad faith fearmongering used to allow the Iraq war, etc.
It boggles my mind that Feinstein has remained a senator for so long in California, but I suspect it may have something to do with the electronic voting machines there. I mean, you could say she has more than enough friends that could help her out with that, especially if she continues doing what she's been doing in the Senate.