I’m convinced ‘ultra-processed food’ is a bullshit term used bully poor people for their lifestyle.
Not too sure what you mean. Ultra-processed food has a pretty standard definition. Briefly, it's food that has been highly processed by some industrial methods.
What about the environmental cost of expensive air shipped food like lobster or the very fancy single origin coffees?
That's a tricky question, but there is a section in this post called What we don’t know, where you could partially find some answers. They explain how difficult it is to track everything down: Getting an exact measure of the environmental toll of UPFs [Ultra-Processed Foods] is nearly impossible, given that, definitionally, UPFs consist of many ingredients and a high volume of opaque processes.