He never ran the show like Eriksen or Kane but this is selling him short. He used to really hard worker on the pitch. The famous Kane mask off goal happens in part thanks to Dele chasing down the "lost cause" ball at the corner.
There was that other famous Kane goal against Van Dijk at Southampton where Dele pokes the ball through to Kane, while nearly getting his legs broken by a reckless challenge.
There were loads of other times where he had a great influence on the game besides scoring/assisting.
He did become what you're talking about in Poch's final season.
EDIT: Actually, at their peak it was Kane > Eriksen > Dele >>>>> Son in terms of technique, vision, workrate. If you asked me 2017 who would have that "assist duo" stat, I'd have said Kane and Eriksen or Kane and Dele. Or even Kane and Trippier, before Kane and Son.