Good lord, this is still being complained about 8 years later? They wouldn't do it in 2013 the first time it was complained about and I don't think it'll happen now. The only value it adds is that players being sync'd down would still have their full kit and avoid a sense of 'loss' from their playstyle. Meanwhile, anyone actually there at-level are left in the dust with what portion of their kit they have access to. To alleviate your feeling of loss you add to others frustrations.

Now, that being said, I do think the level-sync system could be updated by this point in the game. Notably, it'd be nice to be able to level-sync to someone in the party (this currently exists in FFXI and has for quite some time) rather than only level-syncing for FATEs or duties. Would definitely help in overworld (or similar such as Eureka) when someone over-leveled with their party wants to assist some lower-level or newer friends and not hinder their progress or rewards.