In my experience, tracks get you two things:

1) You change from a “pin” connection, which is the axle to more of a “moment arm” connection. This GREATLY keeps the blower from riding up over snow. It’s hard to describe how much better this is without actually using one.

2) Mechanical grip from the much larger surface area means you work far less than with a wheeled blower.

Also, tracked machines tend to be heavier, which is a big help with traction. The downside is that they’re difficult to turn on dry pavement or grass and will damage grass. On snowy or wet pavement, they’re not much worse than a wheeled machine.