Show one fancy 3d game using unity free then
Note, minimalist stylized things like monument valley that don't require postfx don't count (though they used pro too)
looking good is more than having fansy effects lol
if you say "something that looks good EXCEPT if it doesn't require the engine to do the fancy work", you would cut out a) entire generations of video games, b) entire art styles, c) a gosh dang ol' ton of games
you're absolutely right that unity free doesn't allow access to more complicated and pretty rendering effects, but this isn't all you need to make a good-looking game. above all, you need good art direction and design. the effects can heighten the art significantly, but they don't always make the aesthetic.