What IS a worthy Fallout game in your opinion?
This is the problem:
FO3 and FO4 do not offer strategic turn based combat; and probably not even strategic just by itself... That's a deal killer in any alleged Fallout title.
You think a core Fallout element is strategic combat.
I don't see any strategy in Fallout 1. I just don't. It was a matter of having better equipment than the other enemy, and drawing them one by one towards me as possible as I could*. That's what my strategy boils down in Fallout. And that's exactly the same "strategy" I use in New Vegas, albeit with mods, but then again, if mods can make a 3D game challenging, then 3D isn't the problem, excecution is. The difference is that enemies move all the time, and you have to readjust your cover accordingly to stop dying to incoming fire.
I remember my first time playing Fallout. I remember getting owned by the Khans because my character just stood there as everyone kept getting closer and closer to me. This is something that doesn't happen in the 3D games, because my character behaves realistically and can actually move while everyone else is getting closer to me.
If you ask me, I will tell you that 3D games require actual strategy, as long as they are challenging. This is because it isn't a chess match. Real-time is the universe of strategy, of unpredictability. Not to mention if the AI isn't braindead, which again, isn't a problem if you have good AI. In Fallout 1, as I mentioned, I can move the enemies myself through observation as I would in a chess match. In real-time, you have to think on the run. You don't have time to think "well, I shoot, then I move backwards and drain the enemy's AP". No, you must decide quickly, and as you gain experience, you make better decisions. This is where I get huge satisfaction: when I manage to beat the odds and make it out of a place with most of my ammo still on me.**
To a lot of people, isometric makes them feel good for overcoming a fight. Personally, it makes no difference to me. I don't play Fallout 1 for the "strategic turn based combat". I play it because I'm interested in the lore and the quest diversity that also involves multiple ways to solve a quest. New Vegas happens to get both of those things incredibly right, so naturally I think it is a worthy Fallout title.
*this is what I actually did in my second run of Fallout 1, and I beat the Khans effortlessly. I know this may count as "strategy" in some people's books, but it's like me saying that "shoot enemies until they die" is a strategy. I'm just abusing the game in a legal way and I'm not forced to think twice about what I'm doing because I know I will win unless for some reason I'm critically one shotted.
**for the record, I enjoy the switch to 3D because it also makes me appreciate these moments of danger better. I just don't feel as threatened when I see a few sprites come my way and start shooting at me in turns.
tl;dr I believe turn based isometric strategy is an illusion (as opposed to the IE games, for example), and a 3D first person game, as long as properly executed, can make for a great Fallout game, like New Vegas is despite Gamebryo.