I was raised with conservatives (thanks, parents), have eaten dinner in the same room with some pretty high profile people in the Evangelical right, and have been to religious right wing "conferences" and other events. This was back in the late aughts, but one of the most common "big picture issues" (aside from abortion) I remember being talked about was the "INSANE" power that the executive branch has both to do stuff like this and delegated rulemaking (which allows the EPA to set standards without consulting congress, among other things). This was before Trump - the right was seeing the righting on the wall that they would never win a national popular vote again (still haven't) and wanted to limit the already trite authority of the President.

So this, to some members of the right, is bigger than capital. There have been a ton of recent cases in SCOTUS litigating the power of the executive and it's no coincidence that the 5th Circuit 'forced' the court's hand here. The grand goal is to totally neuter the executive branch so they don't have to worry about the Presidency.

The legal arguments are complicated, but the consequences of the 5th Circuit’s ruling, if upheld, would be straightforwardly devastating. First, Jarkesy argues that the SEC’s decision must be vacated because the agency sought civil penalties and disgorgement of unlawful gains in an agency proceeding and not in a federal court, where he would be entitled to a jury trial under the Seventh Amendment. The result would be the demise of agency proceedings if any agency―not just the SEC―sought monetary relief except in federal court. Not all agencies have the statutory authority to bring cases in federal court, and if they wanted the right to recover money from a wrongdoer, today’s stalemated Congress would need to act (it won’t). Even agencies that currently have the right to go to court would have to choose between getting full relief in court or settling for an order stopping the unlawful conduct, which they could do in an administrative proceeding. And to the extent that agencies choose the federal court route, those courts would see a significant increase in complex litigation, with no new judges or additional resources.

Of course, we all know that the executive branch can't really do much anyways. But there are a few important agencies (think FDA) that would end up totally gutted if it went the wrong way.