Note that there are many places that offer tool rentals already. You need a tiller or a log-splitter for a one time project? Just go to Home Depot and rent one for the weekend. Normal garden tools, though, such as shovels, hoes, or rakes are so inexpensive that it’s not cost effective to rent them, because you WILL end up using them several times during the year.
You also make it sound like it’s a huge ordeal to have a small shed or storage unit sitting out back, when it’s not.
And you also miss the point about ownership, by equating something that has no real, physical presence unless it’s given one (literally, digital downloads) with your tools or your vehicle or home. And the self pride and increase in how good you feel about yourself from being an owner. Also don’t forget the corollary to your point — if the individual doesn’t own these things, then some corporation will have to own them so that the individual can rent them. And then what happens if the corporation decides that having this one specialty tool that is only used once every four or five years isn’t worth keeping in inventory?