It isn’t an either/or proposition. There’s multiple ways to both have a viewing and keep a body from getting deep into decomposition, and there’s really no issues with the face automatically becoming grotesque. It really isn’t an every time thing. It isn’t even a majority of the time, when the body is kept cool enough. Pinning isn’t the only option for keeping a mouth closed either.

People have done in home wakes way longer than the funerary industry has existed. There’s plenty of options available.