Earlier quoted context omitted.
A decent tube amp is not significantly more expensive than a decent modeling amp, particularly considering the used market. They're also just as "bulky" as a solid state amp - the heaviest components are the power transformer and drivers. When you start talking about professional gear, the cost of modeling amps is more than tubes. I'd also contest that this is "figured out" - this area is actively researched.
Price and weight are close. About $2500. AxeFx III is about ~6.8 Kg. Between a half and a third of a Plexi head or an AC-30 Head. For a stadium band. It makes the stage setup much easier. No cabinets, mics and low stage volume. Each member gets a rack with two units (backup) and you are done. Sound will be always the same. Less likely to fail. For a small band, you don't need the bulky rack editions. You get the same…
And for a small band even if you have a FoH mix, it's going to sound better out of a 40W combo than through whatever PA your vocalist dragged along. But that's just my opinion.
Digital models do a good job in a vacuum (no pun intended). They do a very poor job of modeling how a guitar and FX chain load and drive the preamp of an real tube amplifier (which is really difficult to capture in either white or black box models). That's also a key to getting lush and evocative ranges of tone from a single configuration.
Just speaking as a player, I don't really fiddle with my tube amps all that much. The tone changes come from dynamics of my hands and controls over my pickup volume controls, and it's accentuated by my drive and boost pedals. That kind of play doesn't translate well to modeling amps which don't have the low headroom, lower impedance inputs of a pure tube stage. I don't need 300 different amp models, I need 1 amp model for 300 tones.