Not sure why you can't see it but the second thread is about 15 tweets that goes through it.
Yes, technically the FBI Director falls under the AG but Biden had made clear he didn't want Wray fired because he was Trump's appointment. If you want to blame Garland, may as well blame Biden. And also the way our judicial branch is set up.
Lots of blame to go around but if you wanted a more proactive AG, you need to look at the person who picked him. Blame Biden for anything at your own peril though.