If you created a diagram using draw.io and now only web browsers can display it somewhat correctly, use this script + manual inkscape editing to fix them.

fix-drawio-svg.py

#!/usr/bin/env python3

"""
draw.io uses foreignObject tags to put fancy text on SVGs.
The structure it creates is like this:

```
<switch>
    <foreignObject>...</foreignObject>
    <text>...</text>
</switch>
```

This is _"nice"_ becase it means that if a visualization tool doesn't support foreignObjects properly,
the output changes completely.
At some point I had the text completely modified in inkscape but my browser was still showing the
old version.

Even their PDF export doesn't support this correctly, let alone inkscape and similar OS tools.
So, unlucky you, if you need consistent SVG display across applications/mediums,
you better use this script to remove the switches and the foreign objects.
You will probably lose text formatting but your SVG will finally show up identical in
firefox, chrome, inkscape, etc...

Bottom line: don't use draw.io even if its layouting features are nice. It's not worth a half a day of fixes later.
"""

import sys
import xml.etree.ElementTree as ET


def main(src, tgt):
    tree = ET.parse(src)
    root = tree.getroot()

    parent_map = {c: p for p in tree.iter() for c in p}

    for switch in root.iter('{http://www.w3.org/2000/svg}switch'):
        children = list(switch)
        if len(children) != 2:
            continue

        bad = None
        good = None
        for child in children:
            if child.tag == '{http://www.w3.org/2000/svg}foreignObject':
                bad = child
            else:
                good = child

        if bad is None:
            continue

        parent_map[switch].append(good)
        parent_map[switch].remove(switch)

    tree.write(tgt)


if __name__ == '__main__':
    main(*sys.argv[1:])