The idea that saving and investing 2k/year "wouldn't make a difference" is pretty funny, since investing 2k/year gets you ~300-400k (inflation-adjusted!) after 40 years (roughly the length of a typical working career).
But that's not really the point, I think. The idea that (most) people remain poor for reasons _other_ than their choices is difficult to credit. Obviously their choices are only the _proximate_ cause; there may be structural factors causing those choices in the first place, but most people who are poor (as in, do not have assets) are not poor because they are being literally robbed at gunpoint. Imagine two people living in the same neighborhood:
Person A makes $30k/year and saves nothing.
Person B makes $35k/year and saves nothing.
Person B is _making choices_ that are different from Person A - they are spending an additional ~5k/year on _something_. You can come up with all sorts of reasons why those choices are reasonable - I sure as heck understand not spending the bare minimum on life's necessities - this isn't a moral judgment! But those choices are being made and they have fairly predictable long-term consequences. If it's possible to live on 30k/year in some set of circumstances, anyone who then occupies comparable circumstances and earns more than 30k/year has a choice to either live below their means... or to not do that. You don't need to call them "bad choices" for this to be true.
Certainly there is a non-trivial number of people whose starting circumstances were such that they truly had no good options, but that's not most people who could reasonably be described as "poor".