Well, in the US things are pretty (unfortunately) locked up. Yes, there are some pre-paid carriers, but the triopoly of AT&T, Verizon, and T-Mobile are pretty incumbent. And although for us, T-Mobile works out well, it depends on your coverage.
Things are a bit different in Canada, particularly in Quebec. There Videotron is tearing it up with their high-speed plans with 20GB a month (wow!) on 5G for $65/month with an annual 100GB a year bonus.
If you don't need that much, the Fizz, which runs on Videotron's 4G LTE network in Quebec isn't a bad choice. It's pretty easy to do, just order a SIM for CAD 10 and then pick your plan.
But basically, the plan is completely roll your own. YOu can get Quebec only, Canada only or US and Canada. You can even get rid of voicemail and save $2/month (who uses that anymore anyway).