Both of these get bundled with the Hardware so people do not really consciously chose them.
And for windows it seems the microsoft actually started to go the ads route by putting them in windows 10 and 11. And you do not have to pay for the OS anymore to use it as you do not have to activate the license.
One example surrounded by many other pieces of hardware that don't do this doesn't do much to solidify your "cannot" absolute.
Edit: Your second link makes it pretty clear that it's not Alexa's lack of profitability that seems to be the issue with regards to ads playing between songs. Apple Music has a free, ad-supported tier - meaning that on whatever device you use it on, you'll hear ads. If your Alexa is set to access your ad-supported Apple Music account, then of course you're going to hear ads.
The obvious counter example to this is Windows itself. Or... iOS?