Does everyone from Naruto's generation have chakra within them? I think it's feasible to imagine some people out there in the world have been born without chakra during the time period where Naruto is alive. I say this because chakra as we learn in the anime was originally given to Hagoromo Ōtsutsuki during a time period in the history of Naruto where no one had chakra, after which she passed it on to her children. Therefore it's presumable that of the other people alive at the time some of them could have continued to have children without ever mixing bloodlines with those who had chakra all the way until Naruto's generation.

Now despite this I can see how considering how many generations it has been there's not likely to be many left who haven't attained chakra, but do you think they are there, and why were they never a plot point for the show?
I don't blame you for asking this question. It is hard to imagine how everyone could have chakra if Kaguya was the origin of chakra, and only a few people had actually descended from Kaguya. But there are some fillers that you have not seen that will explain how.

In one of the late Shippuden episodes, we see Asura Otsusuki, the grandson of Kaguya, teach a bunch of people ninjutsu while he was on a mission to supposedly find water. I think he spread chakra by "donating" it to people. It's either that or everyone has a chakra flow that was unnoticed before Kaguya, and she activated the chakra flow and started the concept of shinobi.