To be clear, it is possible to defend yourself, but ofc no defense is perfect. For illegal activities that might attract federal attention? best to avoid them at all costs. But for general privacy in your day to day life that isn’t practical for most people, and “every cellphone is snitching on you” is way too reductive, even if it’s true in a sense.

For example the person you are replying to mentions Linux phones, many of which publish schematics and make hardware kill switches for the discrete modem a big selling point. That still isn’t perfect protection, but it would protect you from a stingray… and if you have a thought out threat model, you can make the choice whether or not that device is appropriate for your situation.