People use the idea that there's no way to change something simply to relieve themselves of the responsibility to change something.

Somewhat agree. That can happen, but isn't only the case.

In a similar vein, attempts at helping / guiding /advising someone who does need help doing/starting something, are often wrongly called manipulation.

Also as time goes by, I'm comfortable doing my part in the world and not taking responsibility for things beyond my control.

This is despite idealistic young people in one side wanting and fighting to save the world, good on them.

And despite corporate interests on the other side using the narrative of personal responsibility to deflect from their failures.

Conformism is a big part of that

Conflating fatalism with irresponsibility is a popular opinion. There are many paths to this mindset but most are reactive and instinctual, not intentional at all.

For example, the wounded sometimes struggle to find courage, the betrayed sometimes hesitate to trust, and underdogs sometimes give up early. People are people.

It’s important to understand this because scolding or shaming a discouraged or weary person for not doing enough usually does more harm than good. If you want someone to help change something, you must

1. Convince them that change is actually possible,
2. Inspire them with how much better things could be, and
3. Show them what they can do to affect that change.

I think in a lot of cases this is true, but as a flip-side to that, a lot of people use the idea that people should be capable of changing to avoid having to alter their behaviour toward, or expectations of, neurodivergent folks

I completely agree.

If there's one thing people will not do to make a situation better, it's to actually get up and do something themselves about it.

Especially if it requires that person to give without expectation of directly receiving something in return - never mind the concept of "be what you want the world to be".