"Too fast" is relative but the Rust language has had few changes since the 2018 edition (and even that can work alongside the 2015 edition). The pace of change has slowed significantly in recent years. The standard library has had more additions (but Go has had changes there too).
The blog post we're all commenting on started because someone took umbrage to an idea someone else expressed in another blog post. Not because of any actual language changes, not even a formally proposed change, just an idea in a blog post. All the actual changes mentioned ("try!() -> ?, the addition of impl trait, and the dyn keyword") happened years ago. And not all at once. It took years from adding `?` to adding `dyn`.
The blog post we're all commenting on started because someone took umbrage to an idea someone else expressed in another blog post. Not because of any actual language changes, not even a formally proposed change, just an idea in a blog post. All the actual changes mentioned ("try!() -> ?, the addition of impl trait, and the dyn keyword") happened years ago. And not all at once. It took years from adding `?` to adding `dyn`.