So roughly 11% of prospects become regular or impact MLB players? Certainly a much higher percentage get some time in the MLB, I guess it all depends on how you define success.
My son was drafted by the Yankees in 2017 as a pitcher and at one point Clarke Schmidt, Michael King, Garrett Whitlock and my son were roommates (all prospects at the time, all great young men). I watched their prospect stock ebb and flow while they were in the system. Of the 4, Whitlock and my son were not protected (on the 40 man) going into 2021, both were rule 5'd and both have had an opportunity with a different team. I think the system works, all except in 2022 when they skipped the rule 5 - IMO many prospects got hosed there...
All 4 of the roommates are currently blessed to be in the MLB, I wouldn't try to categorize any of these young men as regular or impact players - just getting there makes them unicorns.
I feel like the increased MiLB visibility does nothing but strengthen baseball as a whole. I feel like every minor league ball player has always believed they have a path to the MLB - until they they don't. I'm not sure that more exposure increases that, maybe? - They certainly get paid better now.