I don't think we can really compare Boris to Trump - he isn't on the same scale.
I haven't heard Boris endorsing pussy grabbing as an acceptable way to flirt yet. If he did I'm pretty sure his career would be over.
I also haven't heard him saying stuff like 'there good people on both sides' when describing far right fascists & the people who protest against them.
Trump is just awful and a guaranteed narcissist. Boris I'm sure is a prat but not on the same scale.