It's not about companies getting support for them. It's about building accessibility checks into the development workflow and realizing that accessibility doesn't cost more money; it simply is a process that almost every framework has. WPF, for instance, if the default controls are used (though it works with custom ones, just gotta remember to include the property values), is just a quick look in the properties and ensuring that all of the UIA values are full. Other frameworks such as WXPython, QT5 Accessibility, and so on, exist for other languages and frameworks.