It depends on what you mean by design. Modern proprietary OS (mobile and desktop) certainly have more polish, aesthetic taste and cohesion - that last one bein

It depends on what you mean by design. Modern proprietary OS (mobile and desktop) certainly have more polish, aesthetic taste and cohesion - that last one being the most valuable when compared to much of FOSS. But in terms of usability I'm not convinced they are any better unless we are going back a good 20 years. They have improved looks at the cost of performance and significant ambiguity and thus mental overhead in learning and general operation.