If you just want a device you can slap up, click a button, and use.. well, that's what you're paying extra-plus-privacy for.
However if you want to do a bit of legwork (fingerwork?), this stuff is actually amazingly accessible. Grab yourself some Pi Zero 2 W (or Pi 4 depending on reqs), something from like the camera department or some kind of speaker/mic board or whatever you want. (There are plenty of sources and plenty of hardware variety for this stuff.. adafruit is just recognizable.)
Want a custom voice assistant? You might think Mycroft, but they want signup for most of their stuff.. try Rhasspy instead; a bit of work but actually surprisingly easy to set up, and surprisingly easy to customize. Want a security camera? Search for "raspberry pi camera motion detection" and you'll get articles and videos all over.
With the relatively low cost of the hardware, in a weekend or few you're likely to end up with a better, private network of gear that works how you want, than you would have off-the-shelf anyway.