I doubt Gradio is used more than streamlit. And so does Google [1]
I know that's not exact, but if more people used Gradio, you'd expect at least a somewhat similar number of people searching for it online. Gradio is not even in the same ballpark as Streamlit here.
[1] https://trends.google.com/trends/explore?date=now%201-d&q=%2...
I don't know what to say except that the overwhelming majority of HF spaces are made as Gradio demos and that gradio's whole design makes it far easier to do async things unrelated to reloading the webpage - which is a huge thing for ML/AI demos.
I don't claim you're wrong, but I claim that gradio is far more effectively profitable to know than streamlit is - i.e. Gradio demos are used far more for a top AI paper demo (i.e. NeurIPS system demos) than Streamlit is.