[georgyo]

More specifically, they need a filesystem that both Windows and MacOS can read. No one wants to take their SD card to a friend's computer and have it not work for reasons they won't understand.

The shared set there is basically just fat and exfat.

If Microsoft and Apple collaborated on a new filesystem, or even just supported it, then we might have a possible successor. However even with that, the millions of already shipped devices won't support it. This during the transition period of many years there will still need to be support for fat.

That keeps fat the lowest common denominator and everything supporting it.

[BearOso]

Remember last time they tried a universal media filesystem with UDF? It was implemented in the most incompatible ways as a token gesture by both Microsoft and Apple. These companies want their own, patented, proprietary fs so they can maintain lock-in.

The only way to get a universal standard is to have the community do it and have enough people use it that the big companies have to capitulate.

[ComodoHacker]

The problem is you can't get there without out-of-the-box support.

[babypuncher]

exFAT is a good candidate for a replacement "lowest common denominator" file system, and support for it is growing rapidly now that Microsoft has effectively open-sourced it.

But as you pointed out, in a transitionary period there is still a need to support older devices and software. FOSS purists may also not approve of using exFAT in some situations, since the relevant patents have not yet expired, even if MS has released them to the OIN.