alt Hacker NewsA lot of people made the choice to use proprietary tools for their creative work flow, rather than making do with and pushing for better open source equivalents.
I have some sympathy for them - I am sure they felt it was the only real choice at the time - but not a whole lot.
There were zero open-source options at the time. Flash/Animate was the only digital ink-n-paint solution that was even vaguely affordable to the hobbyist or small studio for many years. Most studio-quality 2D programs were proprietary solutions developed in big studios like Disney.
People started using Flash for professional work around 1995. "Open source" barely existed as a concept then, Wikipedia tells me the name "open source" was coined in 1998 and it took a while before anyone but programmers gave even half a damn about it.
The first open-source studio-quality 2D animation package I know of was OpenToonz from 2016, which was a relicensing of a commercial package that dates back to the late eighties or the early nineties - Wikipedia just mentions v3 from 1993.
But anyway now there is a dude working on an open-source Flash clone that can read the editor source files, so all these people you have next to no sympathy for have something to celebrate.