Two reasons:

First, in many states the electors are bound by law to support the candidate that wins the popular vote in their state. The penalties may vary, but the intent is clear: to make sure people realize it is against the law in that state.

But the second reason is that each campaign actually picks their own electors ahead of time. So it’s not like the state has one set that will vote either way, and who can be persuaded. All of the state that votes for Harris are sending electors their campaign hand-picked, and likewise for Trump. So each side is sending their own very partisan people, whose political success is tied to their party. Violating that will ruin their political career in that party.

This is all a very convoluted system. What we should do is make it much more simple.

Take Harris, and trump. Put them in a big venue, like a football stadium, and then fill the ground level with axes and swords, and shields, and maces (the swinging spikey ball kind).

And just let them go at it until we have a victor.

Then, that victor has to solve a series of puzzles. If they can, they win.

I would also accept a revival of the 1990s version of the tv show American Gladiators. Mostly because I love that show.