Do you have sources on leftist administrations doxing people in the last decade? If not, and it is just randos who are on the left, then you aren't making a valid comparison. Did those leftists have access to every person's information in the way that Musk does?
This is a false equivalency I've been seeing for a very long time: Someone on the right claims that the left is just as extreme as the right (usually they're claiming the left is more extreme), when the people they are referring to on the left are nobodies with little to no political influence or power, whereas on the right the extremists run the entire party and currently control the entire government. It isn't a valid comparison.
There will always be nuts in any large enough group, the difference is that the left doesn't give them outsized power, whereas the right elects them as congresspeople and president.