Sigurdsson "deserved" a start and Bernard "deserved" to get subbed on but neither put us in good shape to win the match today.
I get why managers want to do that but if your game is going to be playing the guys who deserve it then you can't also for example give Pickford indefinite mulligans. Otherwise you've got to make decisions with a longer view and on the basis of what the team needs on the day.
Like I mentioned, you've got to have squad depth because without it, players who just aren't performing (such as Richarlison and its happened with Pickford and Gylfi numerous times) will continue to be played.