A lot of people will opt for the cheaper standard DSL though (<16Mbit), which I suspect is what brings down the average. In the US you have little choice but to pay obscene prices for a very fast cable line, usually with a monthly cap.
FTTB, either through G.FAST OR Ethernet is a better use of all that money in my opinion and it's a lot easier to upgrade in the future (either the building terminal or switcing to full fiber i.e. AON/GPON etc).
Using increasingly involved techniques to get more speed out of a century-old technology is pretty much a dead end.
100Mbit is decent, but it comes at the price of * the wires needing to be very short by telco standards * the use of DSL vectoring, which creates mini-monopolies in the DSLAM and allows one provider (usually Telekom) to hold all users on that DSLAM hostage
And keep in mind that if we had fiber, we could probably get a Gbit.
Make no mistake, the strong position of DSL in Germany is the result of politics, not common sense.
I'm not doubting they actually give you a gigabit connection, but especially during peak hours, I doubt the transit links you hit would necessarily have that much to spare.
For doing backups/restores, in this age of multi-terabyte disks, fast network links (especially in the upload direction) are a necessity.
I don't mind some oversubscription, I can work around peak hours, hell, I'd love to temporarily trade away most of my downlink bandwidth in exchange for uplink bandwidth -- average upload speed is all that matters for this sort of large transfer.
Compounding that, the latency comcast deliberately introduces into their network (I've got many ISP's to judge on here) makes the internet ugly, but only if you don't pay for their services.
What we need is not a target for faster downstream, but higher competition - I could give a shit about network neutrality if the providers offered network honesty: a 500 GB monthly limit is a 1.5mB stream - full stop.