I had a quick look at how many miles you might earn with your trips. Depending on your booking classes, you could well become a Platinum member with Flying Blue or Skymiles, so lounge access should not be a problem (as Gold membership would be sufficient for both programs).
Another aspect: for how long do you think will your travel pattern remain like this? If 10 years is realistic, this would be a pro for FB, because you could become Platinum for life then.