‘Always’ is a little exaggerated (though not completely) - per Flightstats - it was on time 28% of the time over June/July. So always, no.
Has to do with a combo of things. Poor ops out of EWR aren’t out of the norm on any given year, but particularly bad this year. There is some part of that that isn’t UAs fault - there has been some weather and there is always airspace issue in the NYC-area. But this year, other factors are definitely present - stress on the current fleet, staffing (both within and outside of UA), excessive fleet utilization beyond what should be acceptable. These flights also wouldn’t take as much priority as more ‘important’ flights - if they have the staffing and can only ensure, say, the LHR or OPO flights get out on time, guess which one takes priority.
Its 2023, and we’re passed the COVID peak, yes, but the resurgence in demand, without the resurgence in infrastructure is problematic. I suspect this will match will improve over the next 2-3 years, and bring ops more in line with historical trends. But for now, this is what we get.
On another note, I’ve always tended to avoid EWR - not a good airport, a whiff of wind will send ATC delays skyrocketing more than anywhere, etc., so my personal guideline is to give a minimum of 2-2.5 hours of connection time to compensate (at ORD, I’m happy to book an hour or even slightly less). I guess I can be happy that now I’m on the west coast, and while the same issues aren’t completely non-existent, seems to be way better than on the eastern side of the country.