All I know for certain is that I am conscious.
Everything I know is my perception, built in my conscious experience, stored there, and iterated from moment to moment.
I am sensor, processor, container, loop.
A consciousness outside of my own is only as certain as my own experience of it. Whether or not it is conscious in the same way is irrelevant.
All things in my conscious experience, people or otherwise, exist only to inform my loop.
Even if all of you are fundamentally as real as I am, you might as well not be. I can't know for certain.
I will treat you as though you are real either way, ultimately, because it enriches my loop to have interesting inputs.