This comment does not apply for some military and commercial type tires, which the Cybertruck appears to have. One example is the Continental MPT81 commonly found on Unimogs or the DRW to SRW conversions offered by Rickson for brush fire trucks (Usually F450/550 SRW water tankers). There are single rear wheel vehicles with payloads of a lot more than 3,500lbs.
More interesting to me is the way the rims of the Cybertruck have fingers that extend over the sidewalls. My guess is that this allows some type of low pressure operating situation, but it seems like the rim finger could contact the ground, damage the tire, and make mounting really hard.