Tbh, I can't hate the guy for doing this. He is one of the few guys that has given everything to City throughout their historic EPL reign and their first and only UCL win, he has been striving with this team and definitely not a bad idea to put an end to his spell at city.
For his age, going to Saudi and raking in the big bucks is much more suiting for him so he can have more than enough when he retires and can no longer play.
Walker is rank in the top 5 best right wing back in the EPL and no doubt about that after all his achievements and performances at Manchester City just like you’ve said.
I also thought about him going to the Saudi side which is seen to be a retirement option for most players.