What are the options in Düsseldorf for high-speed internet providers?

This post won't give you your answers if you're in the same position as I am shopping around for new Internet connection providers. I'm writing this down for my own reference. Some open questions still remain and some facts still need to be added here.

We're due for a renewal for our Internet provider's cable-modem subscription contract in six months from now. This triggered me to have a look at what the German market has to offer these days. We still have time as being stuck in a contract is one of those annoying things families in Germany have to deal with. Classic mobile phone and internet connection contracts are for the duration of 24 months and require you to cancel it latest two months before the contract renews automatically. Our due date is 2021-05-09.

Reasons to make the switch / what is the issue?

• Vodafone buying Unitymedia some time ago (when?) and how this caused annoying customer service center issues.
• We're stuck with the old Unitymedia contract (3-Play) and we cannot upgrade to the better deal for a lower price as an existing customer. Vodafone enforces the rule that you cannot "down-grade" as in, pay less for a better Internet connection. You can only change by paying more, which to me is one of the main reasons why I want to get rid of this contract.
• The cable modem from AVM is expensive (new about € 230) and it seems we cannot get the rented one from Vodafone (to be investigated as the site didn't let me do it online. I need to call their customer service)

Our requirements

This is our current theoretical speed and cost:

• Download: 200 MBit/s
• Upload: 20 MBit/s
• Cost: Max €60 / month

Changing the subscription should:

• Be around the same or lower monthly cost.
• Preferably have low switching and installation costs.
• Provide us with a more decent router which can withstand IPFS network and has "advanced" features like port-forwarding for my home-servers.
• Optional TV - for the occasional CNN news ... although this is not required as like all modern families we're streaming Netflix and Disney+ for 99% of the time;
• A phone number is not necessary either.

Challenges

1. Cancelling and switching contracts cannot be done by the same person. (Verify this!) You need to wait at least three (Verify this!) months before one can get a new contract under the same name and address with the same provider. Even if the conditions are different.
2. Returning the hardware and organizing the new connection might make us end up without a fixed-line internet connection for some time. Which we technically could bridge using our work hotspots worst case.
3. Essentially Vodafone and Telekom have a duo-poly with some smaller providers fighting for the crumbs. So the costs of Internet in Germany our outrageous compared to other European countries (verify this: What are the Internet connection costs in the Nordics?)

Possibilities

Topics to investigate.

1. Switching to glass fiber from Telekom: not possible in our street as the infrastructure is not yet available, not even in the center of Düsseldorf and there aren't any other providers that can offer this.
2. The Telekom 250 Mbit/s Down and 50 Mbit/s up DSL offer with the LTE hybrid fallback for €60 / month plus connection costs seems the best idea for us - considering our house has a Telekom phone connection already. BUT for that price the Speedport Pro Plus router could have been included. You need to pay an additional €9.95 / month + €6.95 for the MagentaTV Box for the hardware (plus shipping). So that makes it about €77 / month. But since this is DSL, which is the most common connection type in Germany, there are a lot of alternative DSL modems available, including some interesting AVM Fritz!Box models.
3. Switching to the 5G offerings by Telekom or Vodafone: this is very interesting, but it is a very expensive investment still (€80 for "unlimited" bandwidth + €240 for the modem device by Huawei, the HUAWEI 5G CPE Pro 2 modem).
4. Cancelling and returning to Vodafone with their cable modem offer under a different name to be able to benefit from the deals. possibly our best option.
5. Changing to a different cable modem provider: there aren't any valid providers in North-Rhein Westfalen.
6. There are other providers like O2... but their best and fastest DSL is not possible in my house - the availability check only returns me the option for DSL with download of max 50 MBit/s and upload of 10 MBit/s for some reason... Wondering why? Is this because of the existing Telekom connection? When I check the DSL from Telekom offer of 250 Mbit/s, this does seem available.

Open Questions

1. If one gets this 5G router, then one could set up a different computer as our home's DHCP and firewall server and use the router for what it is. To be able to benefit from the speeds of the 5G router, what kind of hardware would the DHCP and firewall router need? I assume a Raspberry Pi 3b would not be enough, right?
2. Is the Telekom Magenta XL 250 MBit/s + LTE Hybrid offer for €60 / month + the one time cost of €76.90 our best bet? We could buy ourselves our own full-featured DSL / LTE router like the FRITZ!Box 6890 LTE for about €309... Need to investigate what deals Telekom and Vodafone can come up with in the next months.

It does look like we're going to be stuck with either Vodafone or Telekom still. So far for a "free market" ... Perhaps our requirements and expectations are just not realistical for the competition to be able to keep up?

It's funny how an LTE connection, at least theoretically, can be faster than DSL these days.

Definitely to be continued...