I didn't intentionally stop buying physical media (movies, specifically) but I can no longer justify paying so much more just to have the physical disc in my closet collecting dust.
Based on the movies I've priced or purchased in the past few months, the average price of a 4K disc is about $20-30, and it takes some waiting before a title will drop below that. Additionally, I've seen titles that are only available in 4K digitally, so buying a lower-quality disc doesn't make sense. And, in some cases digital copies are released before the physical media.
Meanwhile, I've been buying the same movies in iTunes for $10 each. If you check every few days, most new titles will go "on sale" within the first month of release. I just can't justify spending double or triple for physical media, especially when Bluray already seems on its way out.