If you controlled that permanent, draw a card
Mechanized Production, which is also confirmed to be getting a reprint in the MTG Fallout crossover, seems like a great way to do this
It can be oppressive, especially in decks with access to large amount of draw (anything Simic, usually), and Ive found often locks one player out of the game whilst the players with the more durdly value engines have time to set up their less attention-seeking pieces
This results in players having a sense of inevitable loss or anxiety, especially knowing that proliferate exists
I definitely wouldnt rule out seeing him as a fringe option in cEDH either, even though I think that his lack of a third color will hold him back significantly
Mana Confluence helps you keep hands you might not keep if they were instead two or three Temples