I and most other tech-minded people I know switched to Ziggo (the largest/only cable provider) because they could provide 5-10x faster internet at around the same price. XS4All became even harder to justify than when it was just a slightly more expensive DSL ISP.
https://www.xs4all.nl/pakketten/internet/
58,50 EUR a month for 200/20 mbit (if you can get that speed over VDSL2, that is)
https://www.ziggo.nl/pakketten#internet-online-tv#zonder-bel...
54 EUR EUR a month for 200/20 mbit (provided they deliver at your premises)
Where Xs4all is more expensive, is TV, which is actually KPN's.
Previously I had the choice between good quality VDSL2 from Xs4all (or KPN etc) and slightly cheaper Ziggo. That's before they merged with UPC. I consciously picked Xs4all because they deliver a far better service.
YMMV depending on the copper quality of your neighborhood and distance to the neighbourhood connection point (I don't know how to translate "wijkkast").
I have little experience with VDSL2, but in my experience xDSL delivers a lot less than the theoretical max and has a lot more variance than DOCSIS.
People aren’t going to pay extra for a reskinned KPN service.
KPN meanwhile majorly improved their service with extensive free installation service while XS4ALL remained with the useless Gideon offering.
The problem is that the market of tech enthusiasts is very small. At the KPN-scale, it is financially probably more attractive to streamline operations and to lose a few tech enthusiast subscribers than to keep several separate operations.
That said, Xs4all gave KPN the moral higher ground, plus testing grounds for new technology.
Where I live there's no ISP-side firewall on any ISP, so that would not be an advantage at all.
Why would we care if it's only historic events? We'd have moved to another isp and not bothered with a petition.
I wonder whether numbers are related - admittedly when faced with the choice for a new telco I ended up not choosing XS4ALL simply because they're more expensive than other offerings. Maybe they just gradually shrunk, year after year? That'd be an acceptable reason to shut down, despite how great the company is on other dimensions.