1) Trump and company enthusiastically used incredibly activist Judge Matthew Kacsmaryk to hold up large parts of the Biden national agenda, and to feed nonsensical cases to the Supreme Court. Like many restraints on presidential power, people's opinions seem to depend on whether they support the current president.
2) Congress and the Supreme Court can (and do) manage the jurisdictions of the district courts. If MAGA is convinced they are starting a 1000 year Reich and will not be needing the likes of Judge Kacsmaryk in the future, they can change things how they want. If with that power they still allow another free and fair election in the USA, a post-MAGA president might appreciate the power as well.
3) Trump didn't fire those people, the OPM did, and they didn't follow the existing laws when they did. And they didn't claim they inherited some "unitary-authority" from Trump, they just tried to misapply the existing laws, and wouldn't even file briefs if it meant they had to come testify about it