Also could we anonymize the voter that way it’s like any other legally private information that can be accessed with a warrant etc.
https://en.wikipedia.org/wiki/Secret_ballot
https://en.wikipedia.org/wiki/Preference_falsification
https://en.wikipedia.org/wiki/Social-desirability_bias
(I think Brendan Eich's experience with suffering enormous professional consequences for having donated to the Proposition 8 campaign -- a fact which was public under California electoral laws -- is a concrete example. You could imagine the same kind of consequences for everyone who voted for the proposition, in which case many people would not only choose their political donations based on fear of public opinion and social and professional consequences, but would even choose their votes based on those same fears.)
These issues might not convince you, but they represent a sample of other people's answers to your question. Also, in many places, depending a lot on the culture and history, a powerful local figure such as a large employer, union leader, "patron", or religious leader will actively try to tell people how to vote, if given the opportunity.
https://en.wikipedia.org/wiki/Political_machine
https://en.wikipedia.org/wiki/Electoral_fraud#Vote_buying
[1]: https://www.cnbc.com/2020/10/28/2020-election-spending-to-hi...
Voters could be rewarded for voting a certain way.
Voters could be punished for voting a certain way.
You can't get rid of rewards without eliminating capitalism, and you can't get rid of retaliation without eliminating power structures.
Making voter information anonymous except via subpoena doesn't work for the same reason that backdoored encryption doesn't work.