I am also situated in (but not originally from) Eastern Europe. On a personal level I pretty much completely agree with your opinion.
However, that might be in part because I like to take time to prepare food and actually know how to cook. One of the things I love most about Eastern Europe, is that cooking is an art that's not yet (completely) lost on the majority of people (or at least not the female half of it). Be that because of traditional values, a taste/love for quality food (and even knowing what good food tastes like in the first place), or merely a direct consequence of poverty, it still is a quality that should never be underestimated. I firmly believe that many in the West literally no longer know what they are missing.
While growing up, I definitely got the impression that even basic cooking skills became increasing less common knowledge among younger generations in most of Western Europe (I've heard it's even worse for the USA). Arguably it also deteriorated in Eastern Europe, but certainly not to the same extend.
You are right, it isn't just about cost alone. It's also people no longer knowing how to make (healthy) food themselves anymore (or just not from basic ingredient). That said, I myself have been many times in situations (while living in Western Europe) where eating shitty food ended up a lot cheaper than cooking a proper meal. For anyone unable to cook, that will certainly be even worse.
While it might be more of a philosophical question/opinion, one could ask to which extend it's about availability (both referring to ingredients and knowledge) and to which extend it's a question of (bad) choices. It could even be argued that it's the relative luxury (even spoiled behavior) that makes people eat shitty. Marketing, time constraints, and probably a number of other factors might also be to blame (to varying degrees).
Either way, from the statistics I've seen (which should of course always be treated with skepticism), it does at least appear that the poor part of the (Western) demographic eat significantly more unhealthy than the more affluent part. I have often seen the prices of quality food being used as an argument for that trend.
I have to admit, that as someone who can cook a meal out of almost nothing (and at times literally was forced to), I always have mixed feelings about such claims. Still, I did experience myself that living on a budget and cooking from basics was actually a lot easier in Eastern Europe than it was (for me) in Western Europe. It might not have been only about price and availability, but I'm pretty sure that it was a significant factor (for me). A lack of skills sure wasn't a factor in my case. Time constraints neither, since the were the same for me in both situations/locations.