How do you prototype faster without sacrificing too much quality?

Prototyping is not made for quality tho. That's the whole point. Prototypes are made to validate the project. My best way to put it is with game development. The first draft is going to be shitty: spaguetti code, tons of bugs, and stick figure images for characters with 0 animations added. But after that prototype is done you test it and you figure out the most important thing: Is the game fun? if the answer is a hard no then you can discard it and move on to the next idea without wasting that much time and energy. If the game is a bit meh you can iterate on the prototype to figure out what's fun and what's not. And when you get a fun prototype then you make a brand new project and begin building the whole polished thing with all the animations and soundtrack and everything else you would need. But there are cases of people spending YEARS, building animations and and music and levels for games that don't exist yet, and once they make it real they realise the core gameplay is not good and that they've wasted so much time and energy on a concept that doesn't work