Arguably with SemVer as html 1.0 pages still work with no compatibility issues, it will still be 1.x if that is the gate for "breaking" changes. The other way,

Arguably with SemVer as html 1.0 pages still work with no compatibility issues, it will still be 1.x if that is the gate for "breaking" changes. The other way, if you rely on experimental features, it's likely you'll be breaking something every release, ending up with effectively a different major version every release - which is arguably pretty much what we have now. The issue is that for a sufficiently complex environment, the definition of a "Breaking" api change depends on what you use - it's pretty hard to end up making any changes that don't have some visibility across the API after all, even internal details end up leaking.