I agree, and I'm disappointed that the Democratic Party didn't have to change itself more to get this result, but this is a lot more than just winning a few house seats.
The opposition party taking back both the Senate and the House has only happened four other times since 1946 -- notably, in 2018 the Democrats only took back the House. And this result includes states that have basically never flipped before: the last time Kansas had a Democratic senator was 1932, when Democrat meant something totally different.