Oh nice, your technique could then be used succesfully against ANY voting. Right? Just watching the boots. Because keeping the poor or 30% of population watched at gunpoint 24/7 for 2 weeks in Europe so that nobody notices is perfectly easy.
Since there is no way for anyone, including themselves, to get to know how their vote went, if the voting stations are run properly, can be monitored by all constesting parties, yadda yadda, we know how to run this process even in cases where the opposing parties are openly hostile and attempt dirty tricks.
In e-voting, there is no good way against this approach, and local "strongmen" are a realistic threat that actually will get used in contested elections if they are able to. They'd have everyone from their factory to either vote in their office with the supervisor watching over the shoulder or get fired, and there's no good way to prevent that from happening.
1) It's possible to revote unlimited times. In the overwhelming majority of cases, you would get an opportunity to revote in private.
2) If your ID card gets taken away, you can get a new one from the government.
3) If you lack the funds for the necessary travel, the government will provide that.
4) If you're being held locked up against your will, you can call the police.
5) If you're worried about getting murdered after you visibly vote for someone who you don't want to, you can set up a cron job to change the vote after even if you're no longer breathing.
In addition. If there truly is such an adversary that can completely control your life & silence any requests for help, then that very same adversary is also capable of requiring you to wear a hidden live streaming camera when you go to paper vote, so that they can see you really cast your paper vote for the candidate they insist on.
Dreaming up such astronomical edge cases can be useful, but in regards to e-voting, I have yet to see a scenario that has a negative effect on e-voting while the same effect doesn't exist on classic paper voting.
With e-voting, providing ballot secrecy becomes much more complex because at the same time you need to prove that every voted is counted as it was cast.
More importantly, nobody is allowed to enter the voting booth with you. However, there's absentee vote by letter in practically all european voting laws that I'm aware of and that can be used as an attack vector since you can fill it in at home.