When you say "easy to pick up" you may be assuming everyone has skills comparable to your own, but this is a risky assumption. Not all maintainers have the high-level coding skills needed to be comfortable with JavaScript, React and their development environment. That's not meant to be a slur; these are fine people doing a difficult job with many different responsibilities to juggle. Maintenance people are expected to jump in and deal with a host of different problems at short notice, not spend 3 months getting to grips with this or that (possibly obsolete) framework first. I've yet to find anyone at the local CodeUp meetings who would claim React to be easy to learn; most seem to struggle with it for several months before achieving any degree of fluency.
When you say "easy to pick up" you may be assuming everyone has skills comparable to your own, but this is a risky assumption. Not all maintainers have the high-level coding skills needed to be comfortable with JavaScript, React and their development environment. That's not meant to be a slur; these are fine people doing a difficult job with many different responsibilities to juggle. Maintenance people are expected to jump in and deal with a host of different problems at short notice, not spend 3 months getting to grips with this or that (possibly obsolete) framework first. I've yet to find anyone at the local CodeUp meetings who would claim React to be easy to learn; most seem to struggle with it for several months before achieving any degree of fluency.
Note: I am supported in this view by the author of How Fast Can You Learn React?