Trump wasn't any better on gun rights, and Trump's statements on wanting to seize legal guns *first* and ban them afterwards rank among the most disturbingly extreme things any American political leader has ever said.
That was awful and disturbing, however in Trump's defense, I think it was motivated by more of a genuine sense of "oh crap, this is a problem, we need to do something", he just handled it in the most dumb, hamfisted way possible, because Trump. But there was a genuine desire to actually address the issue, as opposed to something like Biden's EOs here, which target "issues" that cannot be be tangibly linked to any sort of criminal behavior, they're almost pure theater.
And given what I know of the people that own 80% and pistol braces, and what their motives for owning them are, the parts of that EO that's not theater I can only describe as targeted retribution against a specific segment of the gun community, namely the "up yours, fedboy" ATF-hater demographic.
Speaking of ATF hate, Biden's new nominee for the postion, David Chipman, has already drawn criticism. Main points so far are that he has a long track record as an anti-gun activist, he's made a number of brazen lies about gun related issues, such as claiming that 50 cal rifles were used to shoot down helicopters at waco, which factually didn't happen and ties into a long history of liberals fearmongering about 50 cals being used to shot down aircraft, despite them never being used to do so or used from any criminal purposes at all. Also, he was involved in Waco in the first place as a "case agent", which I admit I don't know what that is, but frankly any involvement in waco is more than enough to disqualify him from anything government related, unless it's
government housing.
Also so called "Ghost Guns" are almost never actually used in crimes due to how much effort it takes to put them together.
There's not really a lot of extra effort involved in putting together a parts kit and 80% lower, it's more that there's actually next to no tangible benefit to having one. Ghost guns aren't used in crimes because there's no value to an untraceable gun. The cops can get ahold a gun you used to murder somone in one two ways.
1. They catch you with the gun. You are screwed, the fact they can't trace the gun doesn't help you.
2. They find it at the scene, in which case you likely were smart enough to steal a gun from someone else or buy a stolen gun, in which case tracing it will give the cops nothing.
In general, gun registration, gun tracing, bullet casing registration, and similar intrusive measures have either proven useless or only marginally effective (and even gun control advocates admit that in a way, as anti-gun sites that talk about registration don't, or rather can't, point to any times it's had even the appearance of widespread success).