Well, I don’t have a study backing me up, but in my experience, promising what you can’t deliver often results in being called a liar.
I really don’t know why “other candidates do it” would be an excuse. The whole pitch for voting for him is that he is supposed to be better than the other candidates. Seems like whataboutism.
I get what you’re saying on principle, but the reality is that the world does not work like that. There’s a reason populism is often a quick way to get to power, because you just promise whatever people want to hear so you could be elected. People don’t vote based on logic, people vote based on emotion, which means people don’t consider what is realistic, they consider what speaks to them.
You say it as if it was a good thing and not something we should strive to change.
It’s not really about how politics work. It is about how human minds work. The fact that making empty promises and then excuses is more effective than being honest shows one of the reasons why democracy isn’t a good system (although it may currently be the least bad).
And just accepting the lies probably makes it worse.
You might as well just not vote at all because not a single president will ever keep every campaign promise they make. Ever. You don’t have to like it but that’s reality and the only reason to be mad about it for one specific candidate over another is personal bias.
Obviously everyone should vote but unless you’re new to all of this you should already know to pick your battles. If campaign promises weren’t kept you should research it and know why before you complain about it.