@hamatti Note that a speaker maker cannot brick the actual speaker hardware itself, and cannot interact with it if it is never allowed internet access.
The next three paragraphs concern options available to be because of my prior history building guitar amps and pirate radio transmitters.
A bricked "smart speaker" can be torn down, you are guaranteed to be able to re-use the case, the physical speakers inside, possibly the amplifiers and power supplies.
In my case, I could make powered wired speakers rather easily using "op-amp" chips or even discrete transistors. From a bricked or useless without the app smart speaker I would already have everything but the circuit board.
If you have a device with no speaker or headphone jacks, a cheap, no-app bluetooth speaker could be used as a receiver to drive big unpowered speakers using a car stereo amp to power them.
Everything under this is for anyone, no soldering iron required:
First things first: no firmware updates (including bricking your device) can be pushed to a device that is isolated from the global Internet. Printers, speakers etc should be denied access to wifi passwords, and if networked should be networked to a second network card in one computer creating an online network that does not share the Internet connection. That way the manufacturer cannot see the device, the device cannot phone home, and there is no data to sell. Your printer doesn't get the "update" to block third party ink and your speaker cannot serve you ads.
If you want a TV for watching DVD's only, use a standalone computer monitor, these do not contain tuners and should not be subject to any nation's TV taxes etc. If you are not using an RF tuner, a TV is just an overpriced monitor with added antifeatures. I do not have a TV and don't use ad supported or paid streaming services either, so a bare monitor is all I need. Someone else noted here that if you need a big screen you can use a projector.
Any device that uses an app, the cost of a non-activated phone denied Internet access to host that app needs to be considered part of the cost of the device. If the device won't work without an account on the maker's server or won't work when disconnected from the Internet, take it back for a refund. That why I don't buy Mavic drones, though in all fairness those are supposed to be able to run in a short-range, R/C only mode like an entry level drone or cheap R/C plane does without the app.
I would never use the dedicated streaming devices. I don't have any of the relevent accounts or want them, and do not allow ad supported shit into my life.