Gaming

For those who haven't played the series, VATS is an alternate aiming mode where one can pause (or in later games in the 3d series, greatly slow) the game, select a certain number of targets depending upon available action points, and then have all those shots taken in rapid succession, with the game aiming.

I'd say that VATS is kind of a "path" than a purely alternate input method in those games; you need to make a VATS-oriented build, though it's true that it makes it possible to play the game with minimal FPS elements. Like, in Fallout: New Vegas, VATS provides major benefits close-up. While VATS is active, there's enormous damage reduction applied to your character, IIRC 90%, so for short periods of time, they have enormous damage output and little risk. They can also turn rapidly and target multiple enemies, probably better than a player manually-playing could. At close ranges, VATS is just superior.

But VATS suffers severe accuracy penalties at range. Whether-or-not a target is moving doesn't affect VATS accuracy, but range does a lot, whereas with manual aiming, whether-or-not a target is moving makes a big difference and range doesn't matter much. As a result, VATS isn't great for sniping, which is also an aspect of the game. You can do it (especially, oddly-enough, with pistols, in Fallout 4, where the Concentrated Fire perk lets later shots in a flurry of pistol shots at range be very accurate.

In Fallout 76, VATS provides such dramatic damage benefits that I'd say that it's impractical to play a non-VATS build -- VATS is required to get damage up to a reasonable level later in the game.

Tell me you mean that you have played 1 & 2, just not on the steam deck.

Anything otherwise would be a shame.