As someone who isn't familiar with the details of either XAR or SVG formats, I'm curious what makes SVG so offensive? Pointing to the minimal browser support seems like something of a straw man argument given that browser support for XAR is exactly 0. Similarly, I don't know of any print shops that I can send a XAR file to.
There must be some advantages to using a format that is based on widely used standards with lots of existing tools? For example, I just needed to change some object properties in a bunch of SVG files. Starting with no knowledge of SVG at all I was able to put together a Python script that made the changes I needed within a couple of hours. Could I have done this with XAR? I don't know but I suspect not.
Best,
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