This I can agree with.
That's what I described doing in my previous post - both ways: tube amp vs modeler into a poweramp and real cab, set to low volume. Tube amp into a loadbox, cab sims and studio monitors/headphones vs modeler in the same scenario.
I think it's absolutely fair. Those additional features, like a whole suite of fx, can be the things that make the modeler more fun and practical, when played at those low volumes.
They can, but will they find that extra money spent worth it, at what to me sounds like very low volumes? They aren't going to get any of the good stuff going down that low. Maybe they will like the tone more, maybe they won't, but it certainly won't represent that tube amp at its best.
I think the Yamaha THR OP has is already spot on for what they need. Sounds good at low volumes, has pretty good amp simulation, some straightforward fx, headphones option when needed, simple to use, takes little space and doesn't look too odd in a living room.
They might want to add a tube combo to play when the family is out, or cram into a basement where they can turn it up a bit.