Many thanks Emma. If you've not come across this post it's also v helpful from recruiters perspective with some very useful discussion.

I'd imagine the key disincentive would be resource scarcity; the usual barrier to change in organisations. Resource will be needed both to redesign the process and to implement. My very limited experience of EA recruitment - frequently taking 1-2 weeks to respond to an email, missing stated feedback dates, not receiving any notification at all and finding when chasing they went with someone else - is that there seems to be significant under capacity and scope for capability maturity. 

My – admittedly commercial and thus possibly rather cynical - experience with incentives is that unless these are instituted at a leadership level then change seldom trickles down. Until recruitment quality and candidate feedback KPIs are hard-baked into a leadership scorecard / goals, resources won’t be re-allocated to the overworked recruiters / outsource providers, and the process won’t be updated. While there appears to be an oversupply of candidates for roles - which appears to be the current situation in EA - and attitudinal fit isn’t causing significant performance issues, there’s no real incentive to change the status quo other than good intentions.