This is not a phone for people that use their phone like a computer, big phones are popular because a lot of people use their phones for everything and spend hours using them a day, 4" phones are for people who just want a phone to be a phone and think the extra stuff like web browsing is nice to have when they need it in a pinch.
I dont use youtube or watch videos on my phone and use the web browser like once every couple of months to get some info about something or check online prices while at a store, I dont need a big screen to do that. I mainly use my phone for one handed swipe-texting, audio stuff while driving, and GPS, when I got a bigger phone this stuff became a lot harder to do with one hand so I want to go back to 4".