They do this for movies these days but the difference is that physical copies of movies are a dying market. They need to incentivize people to buy physical movies but it's the opposite for video games. There is a large demand for video games in general and people are willing to pay extra for physicals of games because we all know that games can be lost to time.

A game like Celeste wouldn't get a physical release normally so having a LRG release makes sure that people have a physical piece of media that won't be delisted or taken offline because a business no longer has live servers.

I'd definitely be willing to pay a little extra to get a double copy for both formats but I could always resell one or the other and make a profit that the developers/publishers will never see.

The only way this kind of thing would work is if the value of the video game market plummeted and they were absolutely desperate to attract consumers.