So long and tanks for all the friction is what caterpillar tracks would sing if you decided to get rid of them. At face value, hovertanks are much cooler than they are practical.
While a hovertank's locomotion would lack friction, it's as big a strength as it is a weakness. With arbitrarily advanced technology, a hovertank can be arbitrarily heavy and fast, so arbitrarily hard to direct and stop. Remaining stable and accurate when you shoot would be an issue, whereas a regular tank is always the same height and direction, a hovertank's position can vary. Assuming you can anchor your tank when shooting your cannon or getting shot. It won't do you any good against mines, because we would definitely start using anti-hovertank mines as soon as apossible.
You could use hover tanks in really bad terrains, like thin ice, swamps, fording rivers every twelve seconds, and such. Something a flying death machine would be just as capable of. And unlike hovertanks, Unmanned Combat Aerial Vehicles aren't scifi. So unless your typical battlefield consists of 100% dog-awful terrain where air support is consistently compromised, hovertanks aren't really useful.
So does that mean hovering is useless? No. Hovering can still be leveraged... for support roles.
There are other cannon-delivery vehicles than tanks. Here, you aren't going to have an armour problem because artillery cannons aren't really armoured, by design. They're not battlefield units, they provide firepower from the safety of far away. But you still need to move it in position, and this is where hover can open new and interesting tactical options.
Suddenly, your artillery support can be placed anywhere on the map, provided the destination has solid-enough ground. Want to put your cannons on the mountain? Hover it there, plop it down securely, and start shooting.
I think the overlooked strength of hover technology is to make heavy things lighter. This is getting a bit outside the frame, but I want to give you hoverthings, even if they're not hovertanks.
Putting things on a hovertrailer means you can start lifting heavier things. You don't even have to get rid of the wheels, adding some hover-assist already helps a heavy vehicle cross terrain that would otherwise ensare it. You could imagine regular trucks pulling hovertrailers or hover-assisted trailers, capable of moving heavier loads, provided you remember to give it good brakes.
Hybrid vehicles would certainly be more complex and more expensive, but it's worth it if enables you to do thing no other vehicle can. Wars are won and lost through logistics. If you can ford hybrid tanks through the swamp, that's a valuable tactical option. If you can move more troops with a hovertrailer truck, that's an edge.
You could even imagine smaller hovercarriers. Like Boston Dynamics' Big Dog, but without legs and floating. Imagine what applications Hover Dog (™) could be used for. Suddenly you don't need two blokes just to carry one wounded guy to the back. Carrying ammo and heavy guns in combat becomes easy. And you don't need to worry about it getting stuck in the terrain, because it gently floats above.
I know it's not as cool as tanks, but this is practical.