Pi became unavailable because of their business model, not because it got popular and bought out.
https://www.raspberrypi.com/news/supply-chain-update-its-goo...
> Although we are sitting on substantial order backlogs from commercial customers, we expect to gradually increase the fraction of our output which we dedicate to single-unit sales next year until we’re back in our pre-pandemic situation. The chip allocations we’ve received for next year mean that by the end of the third quarter, the channel will have recovered to its equilibrium stocking level, with hundreds of thousands of units available at any given time. At that point, we will have spent a little over two years in a low-stock position: a measure of the severity and persistence of the shortages.
It's been a rough few months to be a pi community member. The 'its totally a supply problem, out of our control' attitude of the company, and then the uncivil outburst of the co-founders wife on the official Pi social accounts didn't do them any favours. That one was made worse by well known and respected former employees chiming in and mentioning that it was how the company was internally probably didn't help.
On the other hand expressif is eating their low end, the pico was too expensive too late. Perhaps they will make a bigger board too. They're much better at integrating with the community than Broadcom, they hired community members like sprite_tm.