That is at least partly Intel's fault for creating CPUs with "configurable TDP-down" and the whole power limit thing. It happens to Lenovos too. There are utilities that can stop that from happening and let you use the full potential of the hardware. There's some discussion about that here: https://news.ycombinator.com/item?id=18425687
Also, their motherboards are not a standard size.
At least they aren't pulling the crap HP does on the enterprise side - requiring service contracts to access firmware updates. This means there's financial incentive to include bugs in component firmware now, to "fix" over time.
Oh yeah, and they also DRM'd drive caddies by integrating a bunch of useless capacity indicator LEDs on the front of the drive tray, because they want people to buy their stupidly overpriced drives instead of buying caddies at $5/pop off ebay and putting bulk-purchased drives in.
For less than two days each.
All returned. The quality control is a joke and I more wouldn't touch Dell with a bargepole.
One XPS 15 powered off every 5 minutes. One had a high pitched whine. In one I had the keys were loose and not fitted properly. In another the hinge was screwed and another became inexplicably hot at idle to the point it was painful to touch.
When I asked to return these they didn't even care why I was returning them.
Back in they day, they went out of their way to use non ATX power supplies.
My first xps desktop was utterly incapable of having all of its drive bays used without said drives cooking to premature failure.
My current work XPS laptop will downclock to 800mhz when chromium has hardware acceleration enabled. Other colleagues have had multiple laptops replaced because theirs downclocked when plugged into AC.
Dell is no better in quality than most of the MFGs who died in the 90s and 00s.
(As a random aside, I loved how HP would use a nice ASUS mobo and then trash everything else back in the day. We used to joke those little cases were what an Antec 1080 pooped out)