It’s because, most people concerned with it, are paranoid and not worth the resources required to actually pull off an exploit like that. We see a lot of “crazy folk” who think they are for some reason “important”. No, you’re probably not the next Edward Snowden, is what it often boils down to. Notice that Snowden didn’t hang around inside of the US after he made revealed his documents?
Secondly, there isn’t a whole lot of options in regard to this, unless you’re willing to settle for extremely old (10yo old laptops) or expensive hardware.
If you were someone that is a specific target of nation state’s intelligence services, simply using “different hardware” won’t be sufficient anyway. They will have the time to dedicate to old fashioned methods such as secret cameras, recording devices, or people photographing you.
Simply put, it’s difficult to evade such an adversary for long periods of time and requires quite a bit of other tradecraft to do so.