As a fellow embedded dev, I think that any system where you run a regular, meaningful risk of bricking with updates is a badly designed system. Other than that, no disagreement. CI is a cheap, fast first step in validation. It's not the stopping point.
Well, I don't do embedded anymore. I enjoyed it, but it can be nerve-wracking.
I write end-user application code, for Apple devices, in Swift. I really enjoy that.
I also do some backend stuff (in PHP). It's not my forte, and I like to avoid it, if possible, but I'm highly skeptical of a lot of backend stuff, these days, and like to know who I'm letting in the back door.
I'd like to do some Bluetooth stuff. I've written a bunch of BLE stuff (even given a class in it[0]), but I haven't found a venue that gives me an excuse (the Meshtastic stuff looks like it might be a good bet, though).