Unfortunately, BK's tenure is in part why Everton is in trouble. Very few can see into the future with real success, he tried and it could have gone better. Right now it's hard to say it could not have gone much worse, albeit that first season after
Moyes with Martinez so nearly ended in CL! But then we lost the values (that Dyche is re-building) that led to our decline. But COVID, Stadium costs and the related loans were difficult to foresee, as were managerial failures (e.g. Koeman).
He has died, probably quite heart broken at what he was unable to resolve successfully. Possibly aspects of his own character contributed to that. He has died, out of respect the club should move on.
I hope that perhaps in a coupla seasons when we're in a) the Prem AND b) BMD, something in Everton's excellent community work can be done in his name. It's an aspect of the club that endured during his time, successfully.