Because just like the most "open source app reading/writing proprietary format" scenarios, it doesn't do it perfectly.

Even if you simply import a .psd and re-export it again as-is, it will still break things like smart objects and layer blending options.

It's not Krita's fault: .psd is not an interchangeable format. Implementing .psd support perfectly is basically implementing the whole PS itself. It's all the artists' "fault". But it doesn't change the fact that using Krita makes my days difficult.

And I believe .psd is still the only "raw" common format for artistic drawing, right?

I've once seen a .psd that won't display correctly in neither Ps or CSP, supposedly because it was exported from something else. That didn't seem like a fun situation.

And PSD is notoriously complicated. I remember reading some rant by an open source developer and there were things along the lines of different endianness in the same file.

It’s a 30+ year old format that went to multiple transitions. I don’t envy the poor soul that has to reverse engineer it.

> I remember reading some rant by an open source developer

This one? https://github.com/gco/xee/blob/4fa3a6d609dd72b8493e52a68f31...

Fantastic read, thanks.

That’s the one yes, thanks.

I took a look at the git blame, and the commit title is perfect.

https://github.com/gco/xee/commit/750196023da5457d9535b30299...

My favorite part is the immediately followed //sanity check, too apt.

> Krita makes my days difficult.

Or maybe the huge goliath that gives less than 0 shits about interoperability makes it difficult?