Bigger wheels and fatter tyres are becoming popular (for good reasons) and that does pose some problems.
It doesn’t, though. I have a set of 29er 36s that’ll take a 3.0 650b or a 2.6 29er without even trying. Boost hubs actually make no difference at all to the crown arch shape and spacing, that’s independent of hub width.
As for wider hubs for stiffness… There’s other ways to achieve that without turning fork standards upside down. Taller flanges, better wheel builds. Most manufacturers didn’t care about this stuff til it had a catchy slogan to make it easy to sell. In fact the trend towards straightpull hubs means that a lot of boost wheels will have smaller flanges which works counter to the triangulation of boost. And many Plus wheelsets will still be flexy because of the parts chosen and build quality (of course the blurb will say “stiffer because boost”
(my 29er wheels are varying stiffness because of the parts I chose- but tbh my everyday wheels could do with being less stiff. All on oldschool hubs.)