So, asking the past defenders of such a situation again, was XUL really worse or is it in effect the same?
Except XUL also allowed such customization that very rarely an extension would become as popular as they become now. Fragmentation as a defense.
(That refers to the discussions about Firefox dropping XUL in the past, killing many-many good extensions and ways to make them and alternative browsers built on XULRunner.)
TL;Dr: Browser extensions are malware sleeper agents.
So, asking the past defenders of such a situation again, was XUL really worse or is it in effect the same?
Except XUL also allowed such customization that very rarely an extension would become as popular as they become now. Fragmentation as a defense.
(That refers to the discussions about Firefox dropping XUL in the past, killing many-many good extensions and ways to make them and alternative browsers built on XULRunner.)