For instancen we can keep our number when switching carriers or unlock phones after the contract's finished.
I'd say regulations are needed in order to keep the market from degrading into customer-slavery. :)
This has also been possible in the U.S. for as long as cell phones have been widespread. Presumably there is a regulatory reason because I can't imagine a strong reason a carrier would implement it otherwise.
For values of "as long as" shorter than fourteen years, that is:
In the US, local number portability was mandated by the Federal Communications Commission (FCC) in 1996 with the First Report and Order on LNP and Number Pooling.
Those of us who owned cell phones in the early 1990s remember very well how screwed we used to be.
The time when regulators gets their eyes open to this problem, is about the same time that regular customers do the same and get ready to leave the incumbents. Best case, you've regulation that says the carriers are supposed to do something they were already going to do, worst case you stripped a potentially disruptive play of it's advantage.
Netherlands: cheapest rates, entrenched incumbents, good service, unlocked phones, number portability
US: more expensive, entrenched incumbents, middling service, locked phones, number portability
Parent's model more closely matches reality! We have a winner!
This particular market has never been free in the way you seem to think, and the "disruption" you are hypothesizing has some extremely high barriers to entry (first rollout a national infrastructure, second ...), which have prevented it from occurring at all.
This is also reflected in the outrageous prices for roaming - this market is not opened up.
I suspect the case in the US is that the carriers aren't forced to open up in the same way.
But, the essence of my disagreement with the GPs post is the idea that entering a two-year contract to get a subsidized phone is "customer-slavery", "clearly" in need of regulation. Just get an unlocked phone and a monthly/pay-go plan. (Putting an APR on the contract I could get behind, though).
I've done that, and with my actual usage pattern it's significantly cheaper over two years (actually, I've been upgrading more like every year for a while), because I also don't need the big plan I'm forced into when buying subsidized. I haven't done the math counting in interest on buying the phone, but I'd be surprised if it didn't still come out cheaper.