

Whether it is referred to the DOJ or not is not my point. What I describe is how this process works. Congress having a simple majority of one party with an adversarial president is unlikely to result in prosecution or impeachment/removal by the Senate because of the systems in play.
For the president, what you say is true. But there are others who are not the president and have participated in illegal activities. This is also being blocked currently by the DOJ or by pardons.
Democrats alone do not have the ability for removal via impeachment. They’d need Republicans to cross the aisle on it and recent history has shown that this is unlikely.
Voters want accountability but there are more obstacles to overcome within our existing legal framework before that is realistically possible. This is why there may be a focus on other more easily altered areas in the short term.



This is a really great question! You’ve already got the underlying reason down too - all the various executive departments were created to distribute the enormous administrative burden of figuring out how to enforce laws that have been passed.
Interestingly, Congress is actually in charge of creating the various departments. The President is not authorized to abolish or create new ones, or to expand their jurisdiction or invent new powers, however they are responsible for proposing leaders to each and soliciting their guidance for topics within their domain. How this currently gets enforced is part of the issue however.
Independent agencies also exist that do not explicitly fall under the authority of the President. While the President can remove heads of departments for any reason, there is a much higher bar for removal of independent agency board members.
As the office of the attorney general is one of the government’s oldest, established during the first Congress, this may be a matter of combatting tradition more than anything else! This predates independent agencies by something like 100 years.
I should also edit in a clarification that the DOJ not being an independent agency is what allows it to be more partisan than something like the FTC. Also that an independent agency does not in and of itself entirely mitigate partisan politics from its decision making.