This is how the GOP works now. If they can't get you to back down, they'll go after your family. And it's a pretty successful intimidation tactic. It's gotten congressmen to refuse to vote or even speak against Trump out of fear of retribution. It got Hunter Biden convicted. It got one of their own state senators to quit the race once Trump and his followers decided he wasn't Trumpy enough for their liking.
But what's more important is what effects it has downstream. Prominent politicians have resources at their disposal to handle threats, and even they still have to worry about this shit. Your average joe doesn't stand a chance in hell. How the hell is your average joe supposed to protect themselves against a lone wolf attacker that could strike anywhere without warning? Where are they going to get the money for security? Are they just supposed to quit their jobs and go into hiding every time they get doxxed? Your average joe has absolutely no chance in hell of surviving the Trump Hate Machine, and no way to gather the resources necessary to even try if Trump wakes up tomorrow morning and decide that, for whatever reason, they're the new target of the day? Ask the two election workers from GA how it is.
The GOP knows this and are capitalizing on it. They want the message to be loud and clear: Get on board, or get run over. They've attacked multiple family members of multiple people with infinitely more resources than you to get their results, and they'll go after you and your family too.