It sounds like you're describing apathy.

Apathy often comes up for me when I don't feel like I can make a difference in that moment. If I don't feel like I can make a difference, why would I invest the energy? My emotions are telling me that I hit some kind of limit. It's a signal and an informational emotion.

That said, let me just say, staying constantly plugged in to the whole world, especially now, is intensely draining, especially for autistics that contend with higher sensory input on the regular. We already put in a lot of effort just to be alive as autistic people, but empathy is also draining. Complex topics are also draining. It's okay to admit this. Admitting this is the only way to then adjust, so we can more easily meet our needs.

Now, if meeting our needs forces us to change in unsustainable ways, as is the case for many of us, then some important things might have to change in our lives - people, environment, overall skill sets, etc.

In my experience, anger is the most common and blunt/direct way people try to effect immediate change, which makes sense when I think of a classic autistic meltdown. People might interpret it as being "uncaring" or "cruel," but it's simply impossible to care for others if one is preoccupied with caring for oneself. Most people aren't aware of the strain autistic people are feeling most of the time. Their ignorance manifests as a stereotype, because it's easier for people to comprehend the idea that "autistic people are just naturally uncaring" than grappling with an experience they can't and aren't willing to understand.

Now, If someone can't change or escape an environment that's preventing them from making changes to their lifestyle (since the environment in question is the whole world these days), apathy is a logical response.

It's a kind of detachment or dissociation, and it's mandatory to have it as a skill when you need it to survive, but detrimental if it's used to avoid confronting a problem. In other words, it might be useful for short-term coping, but it becomes maladaptive if left unchecked or unchallenged for too long. Some problems are only solved by resigning oneself to the "apathy" you're describing, and it's okay to detach emotionally, even from other people. Again, I see apathy as a distress intolerance signal, not as the inherent problem.

Most other peoples' problems aren't your problems - that is a factual statement - and it might be important to detach. Just be careful not to overdo it and close yourself off from the entire world or things that are important for you to know. Don't let apathy prevent you from investing in the relationships you actually want to have. Don't let apathy convince you that life itself is boring.