There are some minor downsides, you can't walk 5 minutes in downtown Toronto without smelling weed. I can tolerate it just fine, but some people hate it. Otherwise it has been great.
I don't think it was supposed to replace everyone in IT, but every company had system administrators or IT administrators that would work with physical servers and now there are gone. You can say that the new SRE are their replacement, but it's a different set of skills, more similar to SDE than to system administrators.
[broad group] has not been okay since [the thing] happened.