It's highly likely that you destroy the phone when trying to manually destroy or remove the cellular modem on modern devices like the Google Pixels. On airplane mode it will be deactivated though (hardware-wise), because that's required by law in order to not confuse the airplane navigation systems on a flight (although that is also unlikely to happen).
So if you use airplane mode at all times, your risk is basically reduced to turning it off by accident, somebody turning it off on purpose (by calling an emergency number for example) or it being turned off due to a software bug or exploit. If your threat model requires the hardware to not be present in the first place, a Pixel Tablet might indeed be your best bet.
If you are worried about being bugged through your smartphone camera or microphone, these can be removed or disconnected much easier hardware-wise (let's say as easily as replacing the battery, you still have to get past the glass or plastic and access the hardware). You can then use an external microphone/headset and connect it whenever you need one. You could also physically block the camera with tape or connect a mic blocker to the USB-C (or on older devices to the audio jack) which will report as a microphone and cause Android to default to that external hardware when mic permission is accessed.
I personally trust the global mic/camera toggles on GOS, but I used to physically block my selfie cameras before using GOS so I understand your concerns. Your options are somewhat limited here. Probably the best way for more extreme threat models is not to use a phone at all in situations where all tracking possibilities must be avoided, and use a laptop with Tails OS occasionally when you have to share files or information. You might also want to check out this video from The Hated One because tracking on the streets can be done in other ways through facial recognition, walk patterns etc.
Just make sure you have a clear threat model first and know exactly what you need to protect, because what you try to achieve comes with a lot of hard work and inconvenience, and one mistake could render your efforts worthless. It might not be worth it and you should only approach it after you have prepared and won the battles that are more likely to harm you (the apps you use, the sensors and radios you turn on, the patterns and habits you follow etc). Thanks for reading this far, I hope it helps.