TBH it’s always about your idea of “allround”- the Hillbilly’s superb, but it’s definitely a “soft conditions tyre that can do hard stuff”. Most riders just don’t do very much of the soft, difficult riding where it really earns its keep. Let’s be honest, most do none or almost none. If you do, then the tradeoff of dragging it around on hard stuff and having that reduced traction on the dry is probably worth it, but it’s never going to be worth it if you don’t.
(IMO the Hillbilly like the Magic Mary has been completely outdone by Conti’s Argotal Soft, I think it’s better at everything, all the time… And more so in the areas where the Hillbilly doesn’t shine, it makes no sense that the Argotal is as good as it is at trailcentre hardpack etc. But, on the other hand, the argotal costs a million pounds and only comes in like 3 versions so far)
I’d disagree with Ben on the Minion too, it’s a superb tyre but “one tyre for everything”? Nah. It’s pretty much a 3 season tyre for me, it can do mud/soft/slippy especially in the maxxgrip but it runs out of steam at much the exact point where I start really wanting a tyre to keep me upright. I would never choose it to go and race at kinlochleven, or for a day of winter fort william offpiste survival, it’d be the difference between riding and walking, or riding and crashing. And that’s OK, because it’s so damn good all the rest of the time.
And like with the hillbilly, most people don’t do much of that sort of riding where the minion is struggling. But that’s “one tyre for everything except” And the same applies at the other end, I never go to a faster rolling front tyre than the minion except for my one xc race a year, but, there’s “everything except” again.
There is no one tyre to do everything, but there is one tyre that’s best for your compromise, and there’s a good chance it’s a Minion.