via the developer of Reddit Enhancement Sweet Browser Extension (a medium blog):
A little over a year ago, Apple announced that Safari extension developers would no longer be able to develop extensions for free. Instead, they had to pay the same $100 per year that iOS and MacOS developers do. The benefit, they alleged, is that you’d get the tools and support to develop iOS and MacOS apps in addition to Safari Extension development. According to them, this “simplified” their program.
The reality is that if your only interest is developing browser extensions, you now have to pay $100 for something that you could previously do for free, with no real usable benefit or improvement to the system. In fact, it became materially worse.
It’s important to note that while you can still publish browser extensions without paying the $100 fee, you cannot have them listed on the Safari Extension Gallery, and they will not auto update when you release new versions. This last bit about auto updating makes it untenable for an extension as large as RES. Tech support is already hard for 5 different browsers on a myriad of operating systems — having thousands of Safari users on older versions of the extension because it won’t auto update would make for a maintenance nightmare.
I can see Apple charging for the benefit of free-advertising on Safari’s Extension Gallery although last time I checked Google & FireFox do not charge you. What’s bothersome is if you acquire an extension via Apple’s Gallery, the developer must continue paying $100 a year so their users can get updates.