I do not think it has truly become a habit if we go by the definition. Although, I hope it does become a habit. But, I do find that over time, I am able to appreciate different things that I may not have thought of deeply before. And that being, writing in my daily gratitude journal.
I chose to make that particular journal a 3 year diary by Midori. Mine is the one pictured below. It is a 10 year special edition blue color. I just started this year with this notebook. My goal was to force myself into a more positive mindset due to my tendency to think pessimistically and my headspace was becoming so negative over the last few years due to job, financial, and health stressors.

I have found that when I do keep up with it, I am more easily able to look at the positives and am able to better realize some of the things that I may have been taking for granted. I have times where I can stop and just take in the small moments and appreciate some of the smaller actions happening around me.
I am hopeful to continue this journal and see where the 3rd year takes me. I hope to get another 3 year journal after this one to span the years of 2027 to 2029 and maybe a 10 year after that or 5 year diaries or just stick with the 3 year ones. We shall see what the future brings.