The protests include rallies, at least all the No Kings ones I've been to. They have speakers for community organizations, unions, and local politicians or people running for local offices who make it publicly known that they are standing up against Trump's madness. There are calls to action, to mobilize with local groups and to call existing representatives to make our voices heard.
They don't bring out the guillotines, no, but it's more than just people standing around being angry.
Anyone who wants to speak at an event or make a different call to action can easily find a way to address the crowd. Bring up your idea with the organizers at your local events, make your case for including Twitter/Amazon/etc boycotts, and see where it goes. These things aren't put together by the untouchable "elites" or celebrities you can't easily get ahold of, they're organized by ordinary people just like you. That makes them relatively easy situations where you can be the change you want to see. Don't let our conditioned disempowerment hold you back from making your case. Your idea sounds solid, why not give it a shot?