I bought an XPS 15, also maxed out, years ago and regretted it also. I had all the power problems you mention, except the random shutoffs.
The machine was not really usable for professional work.
I now have a Thinkpad X1 Carbon 5th gen. It has no major issues and works reliably, even with Linux as the primary OS. Granted, it was more expensive, but well worth the purchase price.
Having experienced a lot of laptop over the years, higher end Thinkpad models are the most reliable. It's disappointing to hear even expensive XPS models are experiencing them same coil whine and battery issues my old Dell laptop had years ago.
Thinkpad also appears to use long lasting batteries that hold charge well. I've had 2 think pads, each 6+ years. They still hold battery for hours and hours.
The XPS 13 would've been my top choice if Dell were interested in taking my money, but they're only willing to sell me one with 16GB of RAM if it also has a pro-glare display. I bought an XPS 15, which came with major backlight bleed. After field circus scheduled an appointment to replace the display the next day and didn't show, I returned it.
I paid $500 less for my X1C5, bought during the Black Friday sale. It doesn't have a dGPU (that I didn't want anyhow); but does have a WQHD display, WWAN, and a 1 TB Samsung SSD instead of a 512 GB Toshiba. No issues with Linux or OpenBSD, and the keyboard is better than both the current XPS 15/Precision 5520 and my 2013 rMBP 13". (Let's not even think about how hard the current MBPs suck.)
I'm totally on the same boat! Failed XPS 15 9550 and migrated to ThinkPad X1 5th gen. Now perfectly happy with the latter.
The XPS had failed with ridiculous reason, I try to access the BIOS/UEFI with some key while boot up. After some tries, the machine never boot again. It founds that by pushing F8 in the wrong timing/combination while booting can cause the machine to brick forever. This is beyond the expectation of how any computer should work !
The machine was not really usable for professional work.
I now have a Thinkpad X1 Carbon 5th gen. It has no major issues and works reliably, even with Linux as the primary OS. Granted, it was more expensive, but well worth the purchase price.