Hi @muffin. Yes, there is maintained, and there are working in updating to a newer version of WebKit, who will be merged in next Beta 3. You can get more details in this thread:
https://discuss.haiku-os.org/t/haiku-webkit-port-patchset/
Unfortunately, web browsers are not an easy target. They had became bigger and complex, in the same way that the web had increased their complexity, and the amount of different technologies. Actually, web browsers are almost as complex as an entire OS.
That means that is an impossible task? Of course not, but surely is not an easy one.
As an example: some years ago (maybe 2012, 2014, not remember exactly) there were big complains about the lack of a complete office suite for Haiku. At that time, looked like a big and almost impossible task. Now, we have not one, but two: LibreOffice and Calligra available at HaikuDepot.
How fast (or slow) we can improve this situation, only depends on how much people contribute to the project. Specifically about WebPositive, in my experience recently their compatibility and stability had been improved, but of course there is a lot of work to do yet.
As a final suggestion, I just want to add that also you have some alternative browsers available: Otter and Dooble, in HaikuDepot. If you can’t use some site in WebPositive, try with one of them.