Most of the bikes we see in Britain are, let's face it, toys. They're not designed for regular, utility use. If they were, they'd have exactly those features you've all outlined - hub gears, disc or hub brakes, chain cases or belt drive etc etc.
Worse, we're snobbish about our bikes (and our cars) in a way that in other nations aren't. I find it hard to believe that some of my colleagues would rather arrive at work covered in road muck and with a sweaty back than be seen on a bike with mudguards or a rack. But they would. I don't know why - no-one would recognise them with their helmets and glasses on anyway!
You can see where I'm going with this. Spend some time in a place where bikes aren't mostly just toys, and yes, you'll see the odd stripped-down road bike - but mostly at weekends. On weekdays, fat-tyred, flat-barred, chain cased, back-pedal-braked leviathans rule the road bike path.
(*Actually, that's a bit unfair. They're often built big, but can be surprisingly light).
Those bikes don't need much maintenance. When they do, they're generally entrusted to a specialist workshop, just as we do with our cars.
A couple of years ago I was working in the Netherlands. I'd agreed to meet a farmer at the edge of a village early one morning. I arrived before him at the field and parked up to wait for him. He was late, and while I was waiting, I saw some of the chaps from the 'executive' village-edge homes setting off for work. In fifteen minutes I saw three guys in suits come out of their houses, briefcase in hand, walk past the BMW/Audi/Mercedes on the drive, get a chunky, upright bike out of the garage or the rack and pedal off to work.
When I mentioned this to a Dutch colleague, he wasn't surprised, but pointed out that they'd have been Executive, expensive bikes. It's enough to own a prestige car in the Netherlands. But it'd be stupid to drive it into town. Stilstaand verkeer is a phrase you hear a lot on traffic reports.