This game is "designed" with less graphical fidelity in mind because it's easier for me to create 3D models of that quality and then it will work on my laptop and phone. That's really just an excuse for me to say I'm not the best at 3D modeling lol but having this game run on just about any machine I threw at it was a priority.
Unity really is a great engine though. I feel it has a lesser reputation as a result of it's accessibility and the many unfinished projects that are associated with it, but Kerbal Space Program, Subnautica, Firewatch, Escpe from Tarkow, Cities Skylines are all great games made with Unity. It's a nice engine that can achieve a lot, especially for what I use it for, so I'd rather stick with Unity and really dive deep into its features rather than dot around trying out many engines and becoming a master at none.