I've never been "burned" by a Porsche dealer.
My first was a CPO '05 Boxster S. It was 5 yo when I bought it. In 2 years and 20k miles it needed nothing except routine maintenance (oil, plugs, belt)-- which I did in about a 3 hours -- the first time I had actually ever changed the oil or plugs in any car.
Second was '88 air-cooled 911, and I did everything myself -- including dropping the engine, changing the sensors, fuel lines, gaskets, valve clearance, and clutch. I did it in my garage with a floorjack and jack stands, with close to zero automotive experience. It never broke -- but it was 25 years old, and had a lot of old and brittle hoses and gaskets. I owned it 6 years, and sold it in 2018 for $18k more than I paid for it. And it is worth $15k more than that today.
Third was a 11 year old '07 Boxster that I owned a short time (1 year, 10k miles), and it needed nothing except belts and an oil change. I sold it on in Texags for $1k less than I paid for it in 2019 (I gave an Ag a deal, as an Ag sold it to me cheap) and it is probably worth $8k+ more than I sold it for today.
My current is new, and I sprung for the additional year of dealer maintenance -- mainly because it was part of the deal to get the allocation at MSRP.
I am a rookie mechanic that came to it late in life, -- totally self-taught on youtube -- and am certainly no expert. But I think my opinion is formed by experience, and not what I read on the interwebs.