You can argue that it’s a better place with him gone

I wasn’t arguing that, but that is my subjective opinion.

but it’s a much worse place because it happened and because people are celebrating

That’s more complicated, i partially agree but I’ll reserve final judgement for a while to see how it pans out.

because it implies that society accepts murdering people who express differing opinions.

I’m not sure how to tell you this, but open pretty much any historical book of any era and you’ll find the same.

I’m not saying it’s ideal and each to their own but i am saying i think it’s naive to ignore the entire history of humanity (and pre-humanity) and expect this current society to be different for some reason.

A large part of the entire history of our species is built on murdering the “other”.

This society and all almost all societies, past and present have accepted/encouraged murdering other groups for stuff and power.

In fact, I’d argue we are better at it than ever.