Link summoning seems like a desperate, "mistake", to keep evolving the game. I mean it's extremely close to just slapping out an extradeck monster just because.
The game just kept going faster faster, soon just summoning a card will give you a free monster out of the extra deck without even needing to materials or something
There are already cards in the game that do exactly that. Neos Fusion, Red-Eyes Fusion, Aleister, Winda, etc. Also, there is stuff like Deep Sea Diva that can give you an additional material for a Synchro/Xyz for free.