I use mine all the time for experiments. They're super useful for doing quick one-off experiments to see if something will work. Sometimes I'll keep using them, other times I'll switch to a different platform.

Friday I was trying to figure out if I could remotely read realtime usage off my power meter. I've tried using a SDR for it but it uses some proprietary frequency hopping system that is difficult to understand and I don't have enough domain knowledge to reliably implement. But it had a debug port on it with what looked like an IR transmitter in it, and some reading online indicated that it might be flashing at a rate that indicates usage. It was too weak (and it was too bright outside) to see it with my phone, so I decided ot just try it out.

30 minutes later I had a Raspi with a IR receiver and lirc and I could confirm that it was pulsing at a rate of 1 pulse per watt-hour (1000 pulses per kWh).

The actual reader implementation I will probably do on esp32 because Raspi is overkill for this, it just needs to read the pulses and broadcast messages to MQTT, and I'll 3D print an enclosure so it's not just taped to the side of the meter. But the Raspi made it really easy to just try this idea out without making any commitments to it. That alone is worth keeping a few around.