Iwobi joined Everton as the transfer window in England neared its closure on August 8 for a fee reported to be in the region of £34m.
The 23-year-old graduated from Arsenal’s academy and went on to make 149 appearances at the Emirates but once the club completed a £72m deal for Lille’s Nicolas Pepe, his position in the first team came under threat.
Kanu, who spent five years at Arsenal and won two Premier League titles, believes his old club erred in letting go of his compatriot.
‘I would say they made a mistake, 100 per cent, Why they let him go, I don’t know,’ Kanu told Goal.
‘He’s a boy who, in and out, is Arsenal. He always wanted to do his best for the club. He loves the club, but not only that he can play football.
‘What he brings week in, week out, the fans need to appreciate that.
‘I think he is still young and those are the type of people you want in the team, people who grew up here, who knows everything about the club and wants to die for the club.
‘He was one of them, so for us to lose him and to let him go, was a shock. I couldn’t really believe we did it, but that’s football.’
Iwobi has made a bright start to his Everton career, scoring two goals in his first three games at the club.