I am still rocking my Dell precision M3800, essentially a 2015 XP 15 with thunderbolt 2 and a quadro k1100 (Today I would just get an XPS).
I got it just after NODE15 and have just replaced the battery and added a second SSD. I now expect more years of service from it. It is still fast enough for most things and I switch between various desktop machines for the heavier lifting.
Anecdote and note to self: Don’t try to flash a custom BIOS in order to hackintosh the machine. It turns it into an expensive paper weight and has to be fixed by skilled people.