Well, landline Internet is not that slow, at least not everywhere
- in the countryside it can be bad, but generally replacement of old cables and centrally used hardware has always been slow, and repairs anyway.
On the street below, there is now glass fiber. In this house with a dozen apartments, we still have copper cables from the 60's (which is the decision of the owners and landlords) - but in the last few years, I never had bandwidth problems (we are also watching TV via the Internet, among other things).
On the other hand, I would agree that mobile bandwidth is often horrible, even in the city. But it has improved a bit in recent years. Compared to some other European countries, we are certainly still behind.
In the past, when I had (obvious) problems with Cloudflare, they often seemed connected to their Amsterdam servers, though.