USB-C makes things kinda worse, in a way.
In the past you could slap together an adapter by chopping up some old cable and slapping it to a new power supply. And things would work, even if voltage or power ratings didn't match exactly, or even at all (although, things would usually work much worse then).
I've jury rigged an adapter for my laptop, which uses a 65w, 20v power brick, to run off a 45w, 16v one, when mine died and I needed to access the files. It worked, as long as I wasn't using doing anything too computationally intensive on the thing.
If the laptops used USB-C, that is very likely would not have worked at all. Chances are, the manufacturer of the smaller laptop would've bundled the cheapest power brick that covers the needs of the machine, so it would've most likely been 45w, 15v over power delivery. And mine would've been 65w, 20v over power delivery. And since everything in USB-C world has to talk to each other and agree beforehand, chances are, nothing would even try to work, even if it, realistically, can.
USB-C is an interface that can be used for a variety of different things. There are different "levels" of power delivery, there's thunderbolt, there's DisplayPort-over-USB-C, etc. And for things to work, the devices on both ends of the cable and the cable itself must comply with any given standard.
For example, on some laptops you can't use a USB-C port with thunderbolt for charging the device, nor the port that supports power delivery to connect thunderbolt devices. While using the same physical interface, the ports are not interchangeable. Even if you're connecting everything right, nothing is going to work if the cable you're using isn't specced properly (and trying to figure out the spec of a cable you have, considering they rarely have any labeling, is, definitely, fun).
If anything, USB-C makes everything harder and more convoluted, because instead of using different ports and plugs for different standards, it's now one port for nigh everything under the sun. If you want things to work, nowadays, you have to hunt down cable and port specs to ensure everything is mutually compatible.