Difficulty inflation is definitely a trend, which is to be expected to an extent as there is clearly a market for it and that market is generally getting more and more skillful with each game they play in the genre. Even within FromSoft for example it's noticeable that they feel the need to one-up themselves with every new release to the point that I felt no desire to try my hand at the Elden Ring DLC. Malenia was already more than enough for me.

I think you're right about smaller studios too, I imagine playtesting and getting the difficulty just right takes a lot of resources and is probably why so many small-studio Soulslikes either end up feeling way too easy or way too hard - both often in an unfun way.