>>96786622
The connection between mana and lands is interesting because scope and scale are contrasted with use.
Across the entirety of the lore Old Walkers and New, their biggest strength was their power to bond with so many different lands and obtain a surplus of mana
One creates a mana bond on the most primal level by drawing upon ones connection to the land via memories of being upon said land (which ties into the concept of the deck as mind). Most people who use magic are attuned to one or two lands generally the one they grew up in and the land they live in currently, at best your going to get a well traveled wizard of renown having three to four to draw upon. However most of their spells don't drain an entire land of its mana all at once allowing for more sustainable practices, Walkers typically use a lot more mana to greater effect which requires time for the land to replenish itself afterwards, which feeds into the quest for seeking out more land to attune oneself to.
Especially since lands can be damaged by overuse or other environmental issues
Take pic rel for example, the land of Dominaria at the time was so damaged that while these pool retained their inherent Blue and White nature you needed to put mana back into them to get and distinct mana from them.