Sentence examples for a reasonably new development from inspiring English sources

The phrase "a reasonably new development" is correct and usable in written English.
It can be used to describe something that has emerged or changed recently, but not so recently that it is completely unfamiliar or untested.
Example: "The introduction of electric vehicles is a reasonably new development in the automotive industry."
Alternatives: "a relatively recent development" or "a fairly new advancement".