Yes, there's a high likelihood we could make improvements in the laws.

No, that would not address the reasons why accountability in law does not yield accountability in practice. ncmncm is right.

The Executive branch is not going to police itself seriously unless there is huge public outcry. Americans' outrage tends to rise and fall at the tempo of (so-called) news cycles.

Even if parts of the Executive branch wanted to pursue accountability, they would run into a hard wall due to claims of "National Security" by the intelligence community. You see how much it took for Daniel Jones and how much he still didn't get. It would require Executive branch orders at the highest levels that the intelligence community must cooperate, and sustained policing under those highest authorities to deal with the intelligence orgs when they try to find ways to argue and dissemble about complying with what they were ordered to do. Even then, staff might just outright commit illegal acts knowing that there will never really be consequences so long as you can claim "National Security". The Executive branch is not going to want to air any of this dirty laundry.

Colby at the CIA tried to be more forthcoming with Congress and that was part of what led to his being let go from his position as DCI.

The Judicial branch isn't going to take action autonomously.

The greatest likelihood of any accountability would have to come via the Legislative branch (Congress) and public outcry. There is an insufficient level of backbone among the people in power in Congress, because it's incredibly easy to be attacked on this politically when it comes to "National Security". There is this incompetent populist mindset that conflates intent with actions. So if the intelligence community or DoD was trying "defend America against those that would seek to harm her or her people", as many will say, you will find no shortage people who wrap themselves in the flag for political or media exposure benefit and assail any politician that would dare to criticize the intelligence community, DoD, etc. Because if they have our best interests at heart, who cares how they go about their business, right? A vocal segment of the populace will lap this up and say that we should be treating America's enemies even more harshly, not kowtowing to emasculated Liberal desires to give terrorists baskets full of daisies.

Also, it will be virtually impossible to air the incontrovertible proof of wrongdoing in the open. No matter what the level of wrongdoing, the highest priority will be placed on not damaging ongoing intelligence operations, methods, sources, and active personnel. As well, there will be considerations associated with airing information that would embarrass or otherwise cause blowback to cooperating partners, like other countries. So you will end up exposed to reports written by people who have seen the stuff that needs the right clearances, but the conclusions will all be more vague and high level and you will also have congresspeople who "disagree with the report", also in a vague way (either because of the political benefits or because they belong to the tribe that thinks the end justifies the means), thereby reducing its credibility and impact.

There has to be a critical mass in Congress that can survive the political fallout to try to do something about this problem, and there has to be a presidential administration that also badly wants to do something about this even if they get skewered publically. That's unfortunately a very tall order.

And yes, writing this all out depresses and saddens me.