My observation has been that the free testing they get is often for cases they never hit in their production use cases.
For example, FB doesn’t use DraftJS on mobile, so it took a whole year long effort and a person who used to work for FB to fix mobile support. They just didn’t need it, didn’t have resources allocated to dealing wit it, and were understandably unresponsive on the subject. Now maybe they can use it in the future on mobile if they want, but they would have just fixed it if that need had ever arisen for them organically.