There’s an old adage “a prosecutor could indict a ham sandwich”* implying that the grand jury is easily mislead - but in my anecdotal experience of serving on a grand jury - this isn’t really true. We definitely said no to overreaches.
And you can also see this happening in high profile cases with the Trump administration:
https://www.nytimes.com/2025/08/27/us/politics/trump-sandwic...
Ignoring that, it’s not clear to me why removing jury trials would reduce the likelihood of a prosecutor throwing a larger number of charges at a defendant. Prosecutors want to demonstrate a record of convictions. That career pressure is still going to exist without jury trials - they’re going to throw anything they can and see what sticks.
*Fun Fact - Sol Wachtler, the judge who coined this, was later convicted of multiple felonies, including blackmailing an ex-lover and threatening to kidnap her daughter. A bit more substantial than a ham sandwich.