Do people here think "no prep" presentations could work? Where it's agreed that nobody will do any prep but simply talk about something they're knowledgeable about? Or share their screen and walk through their current project? Everyone in the audience knows that the presenter wasn't "allowed" to prepare so the expectations are lower, but people still get exposed to other engineers' work.
In that light, I don't understand how you and the OP could consider that it's preventing to do real work. Powerpoint is the real work. And it shouldn't be difficult to justify spending 1-2 days on it, with 100 people assisting to the presentation as witnesses, unless your manager really doesn't want you to give presentations (it's showing off your team so it's good for your manager too).
I get it that it's not part of the engineer mindset of course. If I have to give some advice to strong engineers who do good work, that would be to take credit for your work.
A lot of technical presentations we did are no different than what you would do explaining tech within your team. A few diagrams, and understanding of the core of the tech. Scaling to more than the safety of the team is really where I think people would rather have 3 meetings with 3 different teams to do a knowledge transfer than take the risk of being in front of collecting 5-10 teams worth of engineers.
Looking over the comments, the real gap I expect is the lack of peer management support and encouragement. And expectation that mentoring and teaching peers should be part of the leadership expectations. My view are is the the strongest engineers are the ones that accelerate and multiple the work of themselves and their peers, but there are a lot people who subscribe to the "army of one" 10x engineer philosophy.
Demo, deep dive/narrative on your work. Demonstrating something cool. It was clear the prep was not expected or needed, and it would be scrappy - just like lightning talks at conferences.
The exposure and sharing of ideas was critical.
We even had times where someone would suggest a topic during the meeting and someone would step up and do a deeper dive into it.
Understanding is all relative. You don't need to be an expert to know more than your peers. You just need to accept that your extra knowledge adds value. And be honest where your limits of understanding are.
I haven't been at my current employer long, but from what I've heard about our frequent engineering meetings and their presentations, they do the same thing.
