Backdrop filters were introduced with Firefox 103, which was released just 12 months ago. And it was a major pain for me that Firefox was the only browser I had to do workarounds for this function when Safari supported it since 2015 and chrome did since 2019.
Every platform has some problems. But it’s fairly rare for me to run into these nowadays. I still love using Firefox. But just because your experience is different than mine doesn’t mean that mine is outdated. It’s not meant to be a pushback against your comment, just sharing that there had been issues with Firefox in the past as well.