Lafreniere and Kakko are 19, it’s not unheard of for 19 year olds to be very good in the NHL, especially guys with their pedigree. If they both can’t put up at least 2nd line numbers there’s a big problem
In Mackinnon's first 5 seasons, his best point total was 63 in his rookie season. He followed that up with 38, 52, and 53. Then he exploded and hasn't dipped out of the 90-point range for 3 seasons, and is the cornerstone of a very dangerous Avs team. It took him 5 years to get to that point after going 1st overall.
There was enough patience to go through the rebuild up until now, there has to also be enough patience to let these kids (actual kids) grow and mature in the NHL.