I politely disagree. I have used hundreds/thousands of times in my life the "ELI5" method to explain anything and everything from IT security to budgeting, and it helps people understand. It will bore some of the audience in a call, but it will get the job done.

Kids learn to read with children's books, not by reading Ulysses

There are varying degrees of simplifying things, from purposely obfuscating in order to look smart or fill out your paper to the required length, to sloppily throwing an explanation together, to carefully removing unnecessary complexity and using terms your audience is familiar with, to oversimplifying to the point where there information you're giving is actually bad. Maybe that last one is what you mean by 'infantilizing '.

Always pick the third option, regardless of who you're talking to, to maximize your chance of getting your point across.