Version Mismatch
I've noticed an increasing tenancy for projects to stick to a major version of 0. I found an especially bad case in the README of Kamila Lisp: Every release will be tagged as 0.3.x.y where a bump of x signifies a breaking change, while the bump of y signifies a non-breaking change.
To keep the major version as 0, they had to add an extra sub-version below the patch version and shift the meanings down by one. This exact effect can be achieved through regular versioning by omitting the leading 0 from this new scheme. I think the issue generally comes from a mismatch between how projects are developed and how version numbers work. Most open source projects are developed a single patch at a time, with each patch being released to the public instantly, so there is no instant at which it makes sense to break off into a new major version. By contrast, commercial software releases features in large batches, and so major versions make sense. Another reason for sticking to version 0 is that an increase in major version is a kind of commitment. There is an expectation that some amount of maintenance still happens on older major versions, which may be beyond the scope of a given project. I urge developers to be aware of the reason a major version may not change, and then to actually increment the major version when it is logical to do so, rather than treating it as untouchable.