It’s very different. One is “I will give YOU money if you vote for me” and the other is “I will give EVERYONE money if I win”. The main difference is that one is not discriminating against who people voted for. The first is buying votes, the second is a campaign similar to “I will retroactively lower taxes for this year if I win”, which I don’t think anyone would see as problematic but it’s exactly the same outcome as the one you’re finding problem with, i.e. give people money.

It’s a stupid campaign because anyone with half a brain understand that he’s not going to do it and that that money would have to come from someplace else, but it’s still a campaign promise similar to any other promise politicians make to ask you to vote for them.