I only service my car at the brand dealership and I’m sure it’s both overpriced and often unnecessary. It means several hundred dollars per year (25% sales tax etc). I wouldn’t want to buy a new-ish car with third party service stamps though, so the expensive service does retain some value.

So long as this doesn’t make service even more expensive, at least I’d get something for it that I don’t today. At the moment I tend to instead trade for a newer car once the 2-5 year warranty runs out. This would be cheaper than that at least.