CGNAT is hard at scale, although very few operate it.
On other hand IPv6 is easy.
Also my key point is 'hard at scale', in contrast to yours 'smaller isps'.
I've lived in Canada for > 20 years in several cities and provinces. I'm telling you that CGNAT is extremely common.
I don't think you have any idea what you're talking about.
For mobile Bell uses 464XLAT. Bell mobility is IPv6 only network, also MPLS free, they are SRv6 early adopters, impressive!
Rogers, Videotron mobile use NAT44 for IPv6. IPv6 is native on Rogers.
The fact is ipv4 is scarce, why wouldn't ISPs NAT their customers? Hardly anyone cares, and that's why they get away with it.
I'm now on Bell Fibe and it's a relief to be reachable again, but who knows how long this lasts. But yes at least Rogers is on IPv6...
Happy that Bell Fibe is good for you!
Bell Fibe even has IPv6 in some markers even. ( EBOX has IPv6 everywhere on fiber for years )