I recall Durante making a significantly better version of this thread awhile back that I agreed with. The concept behind your thread is dumb though. Games made in Unity for platforms other than mobile have proven time and time again to run like complete shit despite looking not even remotely demanding. We have every right to be skeptical of games made with that engine.
Here is a list of recent titles built on unity that run great and are generally considered good games.
Night in the wood
Snipperclips
Strafe
Torment
Cuphead
Everything
Clustertruck
I am setsuna
Inside
Pokemon GO
Pony Island
Overcooked
Oxenfree
Superhot
Super mario run
cities skylines
fallout shelter
grow home
her story
kerbals pace program
ori
sunless sea
infinifactory
pillars of eternity
Don't blame the engine, blame the devs - it's up to them to ensure their project runs correctly on any given platform, the engine is simply a base to speed production.
Speaking for the games on that list that I've played, Pokemon GO was shit at launch, several months after launch, and also manages to be one of few mobile games made in Unity that was done poorly. It has ridiculously long load times to this day, is a crazy battery drainer, and despite its intent, it still needs the screen to always be on in order to be functional.
Clustertruck has optimization issues despite its textures being comprised of solid colors, and its geometry being really basic.
Cities Skylines has optimization issues. I can't recall exactly what the devs were saying around launch when people were complaining, but it had to do with limitations within Unity or something.
Last time I played Kerbal Space Program it had plenty of issues, despite looking not even remotely demanding.
I'm playing Pillars of Eternity right now, and I can tell it was made in Unity. Framerate hitching everywhere, and some ghetto approaches toward UI which results in blurry text sometimes.