I find it odd that people are saying they can't play with their friends with a Blue Mage, because you can, just not endgame content from the get go.
You can always go in a dungeon, trial or raid with a premade party. I don't see why you wont be able to go for savage at the end of the day if they'll up the level to max.

From my point of view SE is just beta testing their new idea of a class, its normal that SE isn't going to introduce a potential OP class when there is still prestige content such as Ucob or Uwu being progressed on.

For now just enjoy the beta of the blue mage class, give SE feedback and see how it grows. Personally I like the approach they are taking, this is what makes FFxiv so attractive to play for casuals, not all content that gets released is part of the endgame gear treadmill. Some savage raiders tend to forget that its not all about raiding.

As it is now, Blue Mage can be played by anyone with anyone till level 50. You just will not be able to use the dungeon finder which is fine. I don't want to queue for a Qarn run where 2 Blue Mages can only auto attack and cast one spell. Nor do I wish to be a part of their quest to obtain a certain skill from a specific type of mob in said dungeon which would potentially double the amount of time that would be required to finish said dungeon. You can do this solo or with "friends".