I'm well aware of their claims that they are working on it, but when asked to reaffirm their promise, they bailed. See https://github.com/Pocket/extension-save-to-pocket/issues/75#issuecomment-662564315

As an engineer, I can tell you that the slow progress is almost certainly not out of malice. When choosing between busywork like this and working on actual product features, 9 times out of 10 any project manager will prioritize the product. They've got to keep the lights on, just like everyone else.

And that is perfectly fine in most cases, but not when it contradicts their own manifesto. We are not asking for the moon, just for them to follow their own set standard... You can read it here https://www.mozilla.org/en-US/about/manifesto/.

Vivaldi was never open source and never claimed to be open source. I'm aware of that. And while I would love for them to go the FOSS route, they do adopt a lot of FOSS principles in how they manage the company behind it. They don't act as if they are above reproach, unlike Mozilla. They are not perfect, but as it stand their record is better than Mozilla's.

I would love to use a Firefox fork, but they are all developed by small groups of contributors, which is just not viable from a security standpoint. I came close to switching with Mullvad Browser, but's a bit too limited for my daily use.

Google is evil, you don't have to convince me. And they have full control over Chromium, but the reason the code is open source is regulators. They can use that as an argument that they are not a monopoly. And if Mozilla/Apple were to disappear, it would become even more important to keep Chromium open to keep regulators away. That is one lesson they learned from the United States v. Microsoft Corp. (2001) case when US still had regulations.