I haven’t been able to get even a very simple, small-content game to be under 88 MB with Unreal Engine. The Engine files themselves take up a lot of space. There are ways to cut out the parts you don’t need but currently the build process still thinks you need a lot of stuff and doesn’t make it easy to turn them off, such as Oculus VR libraries for example. It includes those even if I turn off the plugins and even if I don’t use anything related to it.
Maybe someone on here knows how to change UE4 to some kind of “economy” mode though. I’ve heard a few tips here and there in regards to building for Android, for example.
Comparing with car engines UE4 is kind of like a monster truck or a hot rod. An engine that heavy COULD go into a smart car or a go-kart, but it sounds like you are making a car that can only fit a lawnmower engine in it.