As someone who has done both, you can either spend all your time writing complex PBR shaders, or you can spend all your time writing complex gameplay code.
Unity is only "like putting together Lego blocks" in the sense that one very versatile brick and a few fairly trivial bricks are provided to you out of the box, but you'll still need to vacuum form your own set of specialized bricks for the rest of the game.
I am never one to say "don't reinvent the wheel". I think the phrase is universally used by malcontents to berate newbs. I think there is still a lot of value to be had in people starting new game engine projects. But if you want to make a game, rather than a game engine, you should probably be using Unity or Unreal. Making a game in Unity is absolutely a complex undertaking. Just not in the rendering shader code. Which is only a small part of any project.
Unity is only "like putting together Lego blocks" in the sense that one very versatile brick and a few fairly trivial bricks are provided to you out of the box, but you'll still need to vacuum form your own set of specialized bricks for the rest of the game.
I am never one to say "don't reinvent the wheel". I think the phrase is universally used by malcontents to berate newbs. I think there is still a lot of value to be had in people starting new game engine projects. But if you want to make a game, rather than a game engine, you should probably be using Unity or Unreal. Making a game in Unity is absolutely a complex undertaking. Just not in the rendering shader code. Which is only a small part of any project.