Selenium will continue working, and is actively supported by Mozilla. The IDE (the plugin that allowed UI-based recording of tests) is the only thing that's not working.
We knew this was coming down the track, but the selenium project lacked the people to prevent it from happening.
Sauce Labs donated Selenium Builder (nee Sauce Builder) to the project to try and help. Applitools have recently leant some engineering muscle to the problem. The problem breaks down into two main areas:
* Technical: the underpinnings have switched from the XPI model to Web Components. Mozilla are doing what they think is best for their browser, and I know that they make their choices with thought and data.
* People: every successful OSS project has a company or person acting as its champion. The selenium project has people working flat out for the language bindings, the w3c "WebDriver" spec, grid, and supporting the community. We lack a champion with the time to spend on IDE.
We can fix the technical side of things. The thing that we could really do help with is the people-side....
I think that there are plenty of reasons for companies not to contribute. Not many companies have spare engineering capacity for working on OSS. Of those that do, they have to choose where to spend the effort --- testing tools aren't as exciting as Machine Learning, or the latest JS framework, or.... Of course, once you start hacking on the code, you may find you like it a lot. :)
The IDE is a mature, and old product too, so even if engineers can spend time hacking on it, getting up to speed can be tricky. The Selenium project has an active "selenium-developers" google group, a #selenium IRC channel on freenode, and a Slack channel, where many of the core team can be found.
Which is a long way of saying that it's not always easy for even motivated individuals and companies to contribute to OSS.