Does anyone here use newer or custom frameworks aside from TensorFlow, Keras and PyTorch?

I was just starting out with ML and had no clue what I was doing. But eventually, I caught on and started reading about best practices and other stuff and I was reading an article about why most people won’t use newer software frameworks. Specifically, the ones that are still hosted on Github.

I have a feeling people don't want to learn new things because they already worked hard to learn something else. Changing to a new way of doing things can be hard if it doesn't work with what you are already using. And it's hard to convince people to switch unless it’s a mandatory switch.

But I also think choosing a framework depends on people’s needs for their projects. If that project could benefit from that new framework or just use it out of curiosity, people would definitely try it out. If not, they’ll just stick to the popular frameworks (i.e. TensorFlow or PyTorch).

So far what are your thoughts? Do you also use frameworks aside from the popular ones?