You can build any
prototype you can think of quickly, but when taking the game across the finish line I’ve found myself many times pining for some of the mature tooling Unreal offers in the art, character, and netcode areas.
The asset store can be great in general, but it’s rare I’ve used an asset that I didn’t have to modify heavily. I don’t mind that, but code quality varies greatly and sometimes you end up in a spot where you have to go write your own solution anyways for a production project. Art resources are also great for a prototype, but if you want a unique look and feel you’ll still end up needing significant art investment. There’s no free lunch.
All that said, I’d quit gamedev before working in Unreal. It’s great for an artist or a designer, but it’s hell on earth for an engineer. C++ and blueprint spaghetti, no thanks. I can’t tell you how many Unreal devs I’ve interviewed who have expressed this exact sentiment.