I do agree with you, FUSE is perfect for experimenting and figuring out *what* you want your filesystem to do (like cloudflare’s lazy git clone filesystem, artifactFS)
I’m not saying FUSE isn’t useful, I’m saying with agents and sandboxes and this massive race around data access and cold boots, having the logic *in* the kernel is going to become the easiest way to beat your competitors.
Once you *know* the logic you need, and you can implement the features in the kernel, that will become the default.
If it’s in FUSE, it’s still experimental.
To your point about kernel crashes, I think the solution to that is more filesystems that folks can fork and reference. That’s why DirectFS will be open source, and extremely well documented - so that anyone can jump in and play with it, fork it, and make it do whatever they want with a solid foundation