Looking at the universal craze for protein, I'm very glad that no one has yet thought of making "protein-enriched wine".

The industry is so conservative that we haven't even been affected by shrinkflation, no 0.73L or 0.69L for you.

I know of a single and opposite case where, for technical reasons, wine was bottled in 0.7L bottles, but then moved back to 0.75L, and the price did not increase.

The protein fad is a "flash in the pan"; in a couple of years no one will remember it, especially since manufacturers mostly didn't change the composition of products, but simply put protein data on the label.
Products will probably remain, but in a much smaller assortment, and of course there will be a hype around some other next nonsense.

Well, wine will still be in 0.75L bottles.