I can't really count anymore how often omnibar just searched for some local domain I tried to type in, in a search engine, instead of just telling me that domain doesn't exist because I made a typo or whatever.
Having to type https:// in front of every URL is also not very pleasant, especially on mobile phones.
Also browsers assuming that anything outside of PSL is to be searched in a search engine right away instead of resolved as a domain, is another annoyance for this user. At least the browser could be less stupid and consider local search domains part of PSL, but no.
So whether omnibar is more of a hindrance than help depends on the user/use case.
I also kinda like the distinction that ctrl+l is only searching locally in bookmarks/history and ctrl+k is public search.
Users want access to the information they are looking for as quickly and frictionlessly as possible—the omni bar does just that.