Each design approach is superior in what it does best - obviously! First Person perspectives aka Shooters, have a different principle behind it compared to Top Down/ISO perspectives. With the use of First Person you basically are the character you play, where in Top Down and ISO views you actually guide the character, so you don't assume his role.
What is important for Fallout is that with First Person Play you will have always the direct influence of the player, on all interaction, like shooting and moving. The so called Twitch-Gaming. Where in previous Fallout games all of those actions would directly depend on the skills of your character. This was in combat reflected by turn based gameplay and action points, very agile characters will have more freedom in movement, strong characters doing more melee damage and so on. Same goes non-combat situations with speech, science, medicine, and very important the use of it in dialog. It is not a surprise that many people which prefer the shooter approach also applaud the consolidation of Doctor and First Aid, not comprehending why it was actually two separate skills.
Why? Standarts and preferences can change over time. I am not saying that they will completely dissapear. It is right now just a very dominant design approach, and a I can see why. But it also leads to a formula where AAA games start to feel "alike", where Metal Gear Solid Phantom Pain is comparable to Red Dead Redemtpion, where the Witcher 3 is loosing it's focus and becoming eventually a medieval/fantasy GTA clone etc. Those games are not bad! They are great at what they do. But a lot of the diversity right now with AAA games is lost. At some point though the idea might become a bit outdated. I mean of course that is just what I think, no one REALLY knows what will happen.
But the past has shown that preferences can change. That's all I actually want to say.