Because when a debt is paid or you get paid for your work, you don’t feel grateful, this is yours by right.
That sounds like a deeply unsatisfying way to live; it seems like you will mostly be disappointed by the things that are “yours by right” that you don’t get.
The point of gratitude journaling is to focus on how your life has many good things in it. “I got my paycheck for the hours I worked this week; I’m thankful that my employer is honest and prompt, I’m thankful that I have a job, I’m thankful that past-me put in the effort to develop skills relevant to this job, I’m thankful that I live within my means...” and so on. This might involve lowering your expectations so that actually being paid is remarkable enough to write down.
That sounds like a deeply unsatisfying way to live; it seems like you will mostly be disappointed by the things that are “yours by right” that you don’t get.
The point of gratitude journaling is to focus on how your life has many good things in it. “I got my paycheck for the hours I worked this week; I’m thankful that my employer is honest and prompt, I’m thankful that I have a job, I’m thankful that past-me put in the effort to develop skills relevant to this job, I’m thankful that I live within my means...” and so on. This might involve lowering your expectations so that actually being paid is remarkable enough to write down.
In general that’s done by setting a target of at least 3 things to write down every day, so you just pick the best ones.