In the Netherlands the Fritz boxes are seen as one of the 'premium' brands. Most other ISP provided routers are completely shit random value brands so that might explain the difference.
I'm on my third Fritzbox now and only the second one really went bad after 8 years (dropped the VDSL connection multiple times per day) so was promptly replace by the ISP. Current one is a 7583 that's been running really stable for a few years now.
Of course it's a network product: it might also be a spotty hardware part on the other side of your connection. I'd suggest calling your ISP...
