With both well painted plywood and Advantech, the biggest disadvantage isn't life span, but weight.
A big commercial outfit wouldn't be able to carry as many hives on a truck to pollination if they were made of these materials.
Boxes made of them aren't pretty and their manufacture is stone simple, which is a big market-shrinker for them, and part of why they aren't sold by the big bee supply outfits.
Properly constructed and finished, they will last quite a long time, whether some believe it or not.
I'd ask,
"Don, just curious if you have tried this or if it is speculation?"
One material serves on purpose, one another.
Good, painted exterior ply might not last as long as similarly finished pine.. but then again, it might.
Longevity isn't it's attraction, but rather value.
You can make more, cheaper.
And if one did that math on "dollar-years" one gets out of them when properly made, I think they're certainly worth the money.
Plywood is an excellent material for seasonally used nucs, and not a bad material for boxes used year round.
Like pine, used improperly it won't last two years, though.