* Use a few bullet points to put attention on the main points you want to convey.
* Without going overboard, use a tasteful amount of graphic design (bolding one key sentence or whatever).
* Break up a giant nuanced email into sections.
* If something is critical, make it visual: a picture, explainer video, or an infographic can be really useful for something key.
This is harder than it looks. A quote attributed to Mark Twain is "I didn't have time to write a short letter, so I wrote a long one instead." It's a lot easier to go overboard than to distill what needs to be conveyed into the core elements.
Hell, I've learned not to ask more than one question in an email. The first one is the only one to get answered.
Oh hell yes, this is definitely a thing with lots of people. It's one of those WTF realizations that everyone who works in a corporate environment gets slapped in the face with really hard.
There are certain people for which you MUST give 1, maybe 2 sentences at a maximum, address them by name, AND, make sure that they're the only person in the "to:" field. Anything different and you risk ghosting or first-thing-only response.
If there's other folks in the cc who I know may actually read for context, I will add a '"*** details ***"' separator after a few blank lines and then write up normal paragraphs. I know the "details" stuff will get ignored by the target, but that's OK. It's just there for reference and for others who may chime in.