ESPs are great, but their hobbyist ecosystem ultimately relies on the goodwill of a Chinese company that could just as easily decide they want to go the way of Qualcomm, or worse.

Any company can "go the way of Qualcomm", as you call it. To my knowledge, there's no indication that there's any more danger of them going that way relative to, say, TI or ST?

Don't get me wrong, the fall of Arduino is a real loss. Espressif is a company in the business of making money, while Arduino's mission was to build a robust tinkerer ecosystem. Absent an acquisition, it's probably fair to say that Arduino would be less likely than Espressif, ST or TI to do bullshit like this.