I’m careful like this to a point, but you can establish trust with managers. Most decent cultures don’t favor hoarding good employees how you’ve described.

> It's ridiculous to think that helping you build a successful career, which likely doesn't involve them or your current employer for very long, is something that they would do.

This is a very short term perspective. If I am a good manager to you, you are much more likely to stay because that’s an important relationship & you are benefiting. If it means you move on because I helped you gain the skills/confidence you needed, great, maybe sometime down the road you can help me when I’m looking for me next job or refer my next awesome employee. But who cares, at least neither one of us had to be miserable.

You always have to be _cautious_ but don’t let relentless cynicism keep you from good useful professional relationships that can actually help you.

> but you can establish trust with managers.

This is technically true, but metaphorically false. Most readers, especially the younger crowd, are likely to be too trusting and not correctly recognize fundamentally adversarial relationships, like with their boss, with HR, with lawyers whom they don't pay personally, etc. Especially when those people present the relationship with a faux version of the same naivety that they intend to prey upon.

The only people you can trust at a company, are people who have demonstrated that they value your relationship more than the company's relationship. That's not impossible, but if they really need the salary, then the odds are stacked against you.

It's certainly nice to pretend that everyone is nice and trustworthy. In fact, most people will hold it against you if you don't sufficiently pretend to be trusting. Universal insincerity is part of the human condition.