It took Tim Brown about a decade iirc, he’s at 100 TDs and had 9 straight 1k seasons iirc, but he also wasn’t that good/had injuries for the first 5 years of his career.
Kelce isn’t really that great as a Touchdown scorer, like 5th all-time for TEs, about 12 TDs behind 4th as well (Jimmy Graham).
He has a TD this year, his only reception.
