Re: USB-C for power
My Dell is (in day to day usage) only powered by USB-C, which on modern Dells has replaced the proprietary dock connector on the base of the laptop. There is still a "standard" power adaptor, but not the same standard that Dell have been using for past 10 years.
Mine comes from a Dell Thunderbolt dock, which provides 130W USB-C PD, as well as two external screens (one 4k, one 1080p), gigabit wired ethernet and a bunch of USB 3 and USB-C ports for connectivity.
It's nice that everything can be done with a standard system, anyone with a USB-C powered laptop can plug in to my dock and instantly use the extra screens, charging etc. It's less nice that USB-C PD only goes up to 100W, so this Dell workstation class laptop (Precision 5540) that wants 130W can only use specific Dell implementations of it :/
If you don't have such extremes, there are a bunch of very nice USB-C docks doing standard USB-C PD that can be obtained quite reasonably.