This administration is doing things that are illegal. They're getting sued and they're losing. Constantly. But that's expensive and time-consuming for immigrants, which I guess is the point.

USCIS doesn't have the authority to just unlawfully deny a case. It can be challenged in court. They can make your life really difficult. For example, they can put you in removal proceedings if you're an overstayer with a petition that they unlawfully deny and then you're out of status. So now you have to go to immigration court, where the odds are stacked against you, and either get your case approved there or get removal proceedings cancelled. And the administration is holding certain people in removal without bond even if they've been here for decades. And some people, like those on ESTA, have waived their right to see an immigration judge at all.

They prefer what's called "consular processing" (applying outside of the country vs "adjustment of status" in country) is that it takes way longer and the administration has way more power to arbitrarily deny your case, as is the case with certain current banned countries. The Supreme Court ruled the president's power to limit visas to certain countries can't be challenged. The case was from the first Trump term. It's called Trump v. Hawaii [1].

But one thing they are also doing, which is evil, is taking advantage of people come to a USCIS interview without an immigration attorney. They separate the couple and threaten the US citizen that they're committing fraud and to withdraw the case or they get the immigrant to admit things that are false or they just outright deny the case on faulty grounds because people aren't knowledgeable enough to fight back without a professional. It is evil.

[1]: https://en.wikipedia.org/wiki/Trump_v._Hawaii