The South Bay is either boring or very expensive. SF still feels very genuine and has a lot more going on compared to Sunnyvale. Not to say there is no reason to live there, but it seems to mostly attract families who like suburban living
South Bay has much better restaurants than most suburbs, if you like food, and it's not hard to get out to nature. Weather's better than SF and it's a lot cleaner. But if you want nightlife there isn't any, no.