Well, I would love to see browsers implement backdrop-filter asap, But till then I think this method is a way to go for me and few others. Also it’s not hacky, there are lot of things that people make themselves and they look hacky but they work great and they are very performant with great browser support and that’s why other start using them in their production build. When these so called hacky things become popular people start to think of them as one of the best way of doing stuffs. Sometimes it doesn’t matter how you do it, what matters is ,,, does it work great + (performant) and does it has great browser support?

And if the answer is YES then go for it and don’t worry about the rest.