There are advantages to both grafted and ungrafted. Carmine jewell cherries are not grafted and quickly spread through suckers at around year 5
Blackberries like these are not grafted and spread through the ground quickly.
Pears like these rootstocks i grafted after they grew out and established roots. The scion i graft to the rootstock determines how long it takes to fruit primarily. The rootstock once established as long as its a known type produced in a certain number of years. Seedling rootstocks can influence years to fruit though.