I've not played any of them, but Atomic Heart, Hi-Fi rush and Stray all seem pretty solid looking games. Mortal Kombat 4 looks very good.
There were also lots of lower budget and indie games that were better than they would have been without UE4.
Which 3rd party engines have proven to be better than UE4 at producing a range of games
I think it makes development cheaper is the only answer.
It makes it more of a known quantity. The engine is well documented, with a public timeline for planned changes, and with a lot of people who already know UE4 in some capacity or who can be trained up on it due to all the docs and all the other developers to talk to online.
UE will in many cases reduce risk compared to developing tech in house, particularly if you don't already have a strong tech foundation already, or mismanagement has lead to in house platforms crumbling.
UE can also, if you play to its strengths, deliver absolutely top of the line visuals. Nanite is incredible, and changes almost everything in terms of geometry.
Nothing is a best fit for everything though, and having a strong in house technical ability (like The Coalition) will still be needed to get the best out of UE. Which is to say, money and good leadership, will be still pay off.