> Also the point of lithium batteries is that they don't leak, not that they last longer.

Not leaking is part of the point, but it's definitely not the only point. Alkaline batteries have half the capacity (roughly) compared to lithium cells. They also have lower voltages over time vs. lithium cells and are capable of less current. For certain applications (high current draw intermittent, or long life low current) they excel, and leaking isn't really part of that conversation.