One thing I don’t think Cole detractors understand is that he fits a very specific lane for his listeners that Drake & Kendrick do not serve: the appeal to the everyday person. Yes, all 3 artists have songs that do that but Cole does that on every single album and to a higher level.
His fans do not care if Kendrick has more depth conceptually or if Drake puts out more hits, Cole fits a third lane that combines the commerciality with the concepts and delivers it from the perspective of a man willing to drive across the country to show how grateful he is to his fans - you can’t say that about the other 2.
This is not to say you can’t prefer the other 2 (music is subjective!) but I think it’s completely wrong to view his legacy in terms of how he compares to his peers because he’s established a separate lane for himself and will be looked at as one of the greatest rappers ever regardless of what Kendrick and Drake do