This is so definitely not true in many many cases. The best pizza shops in NYC for decades have been quaint, basic and often messy spaces. The ones with the nice menus and overdone decor were often subpar and would fail. This also applies to the best chinese food. Opening a business is hard, you might be incredibly passionate about pizza or coffee but not have budget for a designer. When traveling I usually have way better food at the unpretentious local street food spots rather than the michelin star ones that are all about presentation.