>Deutsche Telekom has no incentive to lay cables, as they will have to share the infrastructure with competitors at a price that makes doing so unattractive.

Seems like a pretty severe failure of government if they actively disincentivised investment into fiber tech...

That is what governments do, make infrastructure more expensive to build.

No, it's due to privatization. The Bundespost would simply lay cables because they're needed, without any silly market games.

The Bundespost would have you rent a slow, outdated modem and disallowed connecting any devices from the private market.

Source: this is was actually happened when they still had the monopoly.

It did, yes, but that policy could have easily been changed without privatization. Private companies often had the same policy ("Routerzwang") until the state stopped them. Whereas misaligned incentives are a direct consequence of trying to manage a natural monopoly using markets.

Sweden has the same regulation but we got widespread fiber anyway

> the same regulation

As in, you compared the regulated prices?

It's been a while since I lived in Sweden but I didn't know anyone with fiber from the incumbent, there were lots and lots of national and local competitors (power companies, municipal networks, other telcos, internet startups, local co-ops)