Fallout 4 was the first Fallout game in the series to feature a fully voiced protaganist, but did this change really end up helping the final product? Why change a trope (the "Silent Protaganist") thats worked perfectly well for many games, especially RPGs? The easy answer is production values, if the game looks better before it comes out it will sell better.
However, did this help fallout as a game? As a story? No, it didnt. If anything it hurt it in almost very aspect, all the way down to mechanics. To fully understand the sheer amount voice acting can affect the design of a game lets look at a classic, Final Fantasy 7.
Cloud Strife is a protaganist introduced as a cocky, reckless, and hot-blooded youth who breaks the rules and has a distinct no-care attitude. He's radical in the hip 90's way, in short he should be read like Sonic the Hedgehog.
Of course anyone who has heard Cloud's voice knows this isnt the case. Voice acting turned a 90's hero into a stoic edgelord. Now I understand Clouds personality change during the game which is reflected by his voice actor Steve Burton very well in Advent Children, but fans and non-fans have latched onto his current voice and overwritten the original interperetation in my opinion.
If you want another example with MANY opinions behind it then look no further than Metal Gear Solid 5. David Hayter the previous voice actor for all versions of Snake was rather suddenly replaced by the "Hollywood Famous" Kiefer Sutherland which caused a fair bit of fan backlash. This is because David Hayters interperetation of Snake was so set in stone by this point that no amount of clever writing could fix it. Even the reveal that your character was NOT Snake (or Big Boss rather) and was in fact just some medic, doesnt really help.
Fallout 4 gets the shortest stick because it has to deal with a much different and pervasive problem, having to record ALL the lines of dialogue for a sandbox RPG. Voice acting is put shortly, expensive and time consuming, valuable resources have to be allocated to make it happen and in the world of video game design, resources are limited even for Bethesda, which is why Fallout 4 suffers from a lack of player agency that previous titles were full of.
When the player exits the Vault in Fallout 3 they can pretty much say "screw dad didnt like him anyway", in Fallout: New Vegas as soon as the player leaves Doc Mitchells Clinic they can do whatever they want even teaming up with the person who SHOT THEM IN THE HEAD, In Fallout 4 you must kill Kellog you have no choice and cannot in fact progress the game with any of the "factions" unless you do, you MUST look for Shaun and you MUST be a good guy doing it even if your perception of "good" is a little warped. There are if the player is lucky 2 ways of resolving any quest in Fallout 4, violence, or a very limited form of persuasion as opposed to Fallout: New Vegas where quests can be resolved by completing other quests in the world, theft, persuading NPCs with items found in game etc. Fallout 4 ends up suffering because ALL lines of player dialogue are voice acted, like i said before those resources had to go somewhere.
A noticable correlation exists between how much a player character speaks inversely affecting the players agency in the game. For example, Fallout 4s protaganist says everything the player chooses to input (granted from an extremely limited pool of options) and theyre hardly able to make any meaningful decisions at all, at least in regards to resolving quests. Compare that to Metal Gear Solid 5 who also has a fully voiced protaganist but, theyre kept silent throughout most of the game, only chiming in to ask questions the player might have and grunt in the affirmative, unlike Fallout 4 though the player has any number of solutions to the "quest" and granted it is also in the form of violence but at least one can be more creative than simply pointing and shooting. Metal Gear Solid allows players to conduct recon to find when thier target is least guarded, lay traps or ambushes, or even to sneak completely undetected not harming a single soul.
Metal Gear Solid 5 understands that a sandbox should have more options than can possibly be spoken, ways that players can solve problems by manipulating the world around them perhaps even in ways the develepor never intended, and thats a beautiful thing.