There is a legitimate reason why only some cutscenes have full voice acting and some don't. The times there is no voice acting is usually when NPCs are identifying your character by whatever name you chose for them. This is not possible with fully voiced cutscenes so for those times your character is usually referred to by some default boilerplate title ('the adventurer', 'the Champion', 'Bringer of Light', 'the Warrior of Light' etc) and thus the scene loses the personalized effect when it has voice acting.

This is why in games such as Mass Effect or The Old Republic the player character has more of a backstory including either being given a default name and ignores the player's chosen name in cutscenes, or only allowing you to choose a partial personalized name with the other half (like a family name) a default name that you cannot change (like Commander Shepherd in Mass Effect, you can change Shep's first name but they will always be identified as 'Shepherd' in cutscenes.).

For FFXIV however, SE however went back to their roots and allowed the player to choose both their names completely by having the player character virtually a blank slate, just like the original FF game (which also had a party of generic no-name characters only identified by their Job class). Thus, this limits voice acting to key scenes, and accordingly your character is only identified by default titles in those scenes. It's a design choice.