From experience I can say that interpretation of Beta & RC varies between companies and developers.
For me and according to Wikipedia too, the beta version is almost ready in terms of functionality. That’s why the word “off” was also in the quotes.

The beta phase generally starts when the software feature is complete but it is likely to contain many known or unknown bugs.

But I understand what you’re saying, I know developers who see the beta as something incomplete, but it can be used partially while it’s still in development

With us, the goal is that RC no longer has any known bugs or it doesn’t need to be fixed before release. It wasn’t called “Candidate Release” for nothing.
It would be weird if you have an RC that you already know you don’t want/will be issued, it’s not a candidate.
Of course, there are often bugs from RC that need to be fixed before release.

So for us, and most developers I know, the beta is almost over, no major additions, but known bugs.
RC becomes available and often has unknown errors that are not found internally.

Release Candidate (RC), also known as “Going to Silver”, is a beta release that is potentially a stable product, ready for release unless major bugs appear.

But as I said, the interpretation varies.