“Sometimes it’s nice to learn that a psychological phenomenon has a name, if only so I no longer have to think of it as Me Being Uniquely Irrational And Self-Defeating. So it is with the Diderot effect – which, I learned recently (via Lifehacker), is the term for when you buy something new, but then it makes your other possessions look timeworn by comparison, so you end up replacing them, too. The inspiration here is Denis Diderot’s 1769 essay Regrets For My Old Dressing Gown, in which he recounts being given a luxurious replacement. “My old robe was one with the other rags that surrounded me,” Diderot laments. But “all is now discordant”. Before long, he’s obliged to replace his furniture and paintings as well: “I was the absolute master of my old robe. I have become the slave of the new one.”

https://www.theguardian.com/lifeandstyle/2015/oct/02/shopping-diderot-effect-oliver-burkeman