Could it be, that a person can be boring, even though they do things? Is it the lack of the ability to express oneself? Lack of focus? [I'd Rather Get To Know You Than Small Talk]

Lack of popularity. If you don't fit in even the most social person will not be included. Has nothing to do with ability nor way of communicating.

In fact some of the least able are quite popular. While the ones with the most abilities rarely are popular.

Knew a gal that had no job, wasn't pretty, could hardly speak good english, in fact she was quite insane. Which was why she was quite popular.

No common interests with whomever you've bored to tears, perhaps.
It's all about finding your compliment.

Delivery really is everything. A skilled individual can ignite passion for any subject, so self expression can indeed be improved.

Remember that conversation is an art, and dying out fast in our isolated world.

I don't think there's a universal pattern to describe boring. Different people think and feel different things. I don't think that self expression or lack of focus are exactly the particular traits that contribute to being boring. I think it's preference of the other; because preference is different for everyone

What? Sorry, I wasn't focusing on what you were saying. 😋

Story of my life.