With paper ballots, I know that there's no way my selection was changed before it was given to the poll worker (who is subject to public observation). With voting machines, I have no idea what the poll worker received.
It seems like there should be some sort of nationwide ActBlue campaign to specifically focus on whatever Sec-Of-State races are relevant for that election season.
Thankfully we can be sure that our votes have not been compromised in the past and there are no actors in the system who might benefit from avoiding looking into possible compromises.
Oh wait..
What motivation do they have to fix a system that put them in office in the first place? (hint: none, there is no motivation)
If you do early voting, you can only vote electronically. If you vote on election day, you can choose a paper ballot if you wish. Early voting is electronic only because you can vote anywhere in the city (if you work downtown you can do so on your lunch break no matter where in the city you live) and there are dozens of different ballots because we vote on things at the neighborhood level in addition to state and national candidates. Having paper ballots would be quite challenging.
Nothing will change until something scares people enough to make them take action.
Of course voter intimidation is a threat, but that doesn't have anything to do with the process of casting and counting ballots.
It's not impossible to change votes on an individual level, but all the attacks against it don't scale at all.
How many votes do you need to sway an election? There are about 50 precincts in my county, which is one of 67 counties in my state.
Even if you somehow manage to rig each precinct flawlessly, that's still a lot of people that have to know about the rigging, over a pretty large area, and not one of them can get caught or the whole thing is over.
And if the elections are done right, there should be a number of people from the public at each precinct watching those ballot boxes all day, counting along when tallying votes, and ensuring nobody casts more than one vote or tampers with the box. Hell, you don't even need to speak english or have gone to high school to help secure an election like this, literally anyone can do it.
Paper ballots don't break down, they don't have glitches, they don't require 24/7/365 security to prevent tampering, they don't require nearly as many ballot workers or helpers, they can't "underestimate" voter turnout and only have 2 machines in a precinct to make people not want to wait hours to vote, and they aren't going to be able to be hacked by one guy at the dock yard alone with a shipping container full of voting machines.
It's not perfect, but it's a hell of a lot better than voting machines, mechanical or electronic.
Pretty much the only option.