I moved from PokerStars to 888 five month ago, and have only been back on Stars a few times since then. But my impression is, that the case games definitely became softer on Stars, after they introduced their 4 table cap a few month ago.
It kind of makes sense, that the table cap might have induced some grinders to take their activity elsewhere, and that cash games on competing sites might now therefore actually be tougher. Which is certainly a turnaround from, how it was for many years.
As for 888 I think, it’s a bit of a myth, that the games there are so incredibly soft. In the early European morning hours, where only few tables are running, they can be pretty juicy. But that is also the case on Stars. And if I log on to 888 after work, there are many tables running, but most of them have low players per flop numbers, so its not like, they are full of huge fish.