Since 2001 I have tried to find a single antenna that would perform reasonably well in all bands and have gain in a few strategic bands like 40 and 20M.
The N6BT DXU-32 covered the strategic bands, but once you add in other bands like 160, 80 and 30 (required for the bottom of a cycle), you all of a sudden need at least one extra antenna.
If you just wanted to get on all bands where you could work DX, a vertical with a tuner would work, but I doubt you’d get to Honor Roll or Top of Honor Roll, certainly not in one solar cycle as I did.
I’m going to go with two antennas to cover 160 – 20M, which would be the bottom of a cycle minimum in the antennas you would need.
To cover higher bands, you could possibly find an antenna such as a SteppIR yagi that covered all bands from 40 – 10 or even up to 6M.
But I think I have exhausted all routes to having just one antenna.