> It's a massive chore to have a teammate that causes stuff like this and I don't envy your teammates or lead (even worse if you're the lead, obviously).
It gets tricky. I haven't had to deal with this friction for many years, but it's not because I entirely avoid the type of directness described in OP's last two examples. It's because I'm careful about who I'm direct with, and because I've ended up in environments that are increasingly devoid of the emotionally-fragile.
I start out with a baseline of assuming that people are as fragile and childish as what your comment alludes to. In many companies, I'm sure this is actually the case. But as I get to know a coworker, it's very often the case that they have the talent, maturity, and emotional stability to handle direct communication (in both directions) without spiraling into an episode.
In my early career, I joined a company with an awful hiring pipeline as the first employee. That was my first introduction to the idea that a lot of people react violently to being treated with respect if they think they don't deserve it. I quickly started treating them like children as you suggest, and the problem immediately vanished.
But as I've progressed in my career, the amount of time I spend around mediocrities has plummeted, and my prior that the person I'm communicating with is a mental adult has risen. I've found that high-productivity professional contexts weed out the emotionally-unstable in the same way they weed out (eg) the disorganized; the value of good-faith efficient communication without mental breakdowns is simply too high.