To be honest, I don't think Barcelona's recent victory against Las Palmas was an easy one; the first half of the game ended in a draw in which Barcelona failed to score a single goal, but they were able to turn things around in the second half. I wasn't expecting Barcelona to win the game because the previous time they played Las Palmas, they were defeated 1-2, despite that, it's clear that Barcelona didn't win Las Palmas easily.
However, the only match I consider an easy win for Barcelona is one where they can defeat their opponent by more than two goals, not one where they are unable to score in the first half and the referee fails to award a penalty for Las Palmas to equalize against Barcelona. Despite the fact that Real Madrid is a big club in the league, I believe Barcelona's victory against them this season to be very easy because Barcelona humiliated them with plenty of goals.
Barcelona sometimes have this, but it's not strange, against such a team the opponents choose defensive tactics and some teams are able to defend much better, so it is more difficult for Barcelona to win, sometimes it can be a victory by only one goal, or a match without goals scored at all. But more often they manage to score a lot of goals, Barcelona has the best attack in La Liga.