In Fallout New Vegas, you would often see a dialog option such as, "You can give me a better price (Barter [ 25 / 40 ] )".... which would mean that you could select that dialog option, but since you only have a 25 skill and the check requires a 40 skill, the dialog option would automatically fail --- you could still CHOOSE it, it just would not WORK. If, however, you had a barter skill greater than the check value, it would just say, "You can give me a better price (Barter)".... and if you selected that option, it would succeed.
There are two issues with how Fallout 4 works, here....
(1) With short few-word prompts for dialog, I can't see them showing us which skills/perks influence a dialog choice. In one video, one of the dialog options was yellow and the others were green, but that could mean any number of things (yellow could lead to further dialog, or could end conversation, or could be reliant on some skill, etc). This could mean that you simply don't even ~see~ an option unless you have the perk/skill/stat sufficient to "succeed" at it. The down side to this is that you don't know what you missed. More reason for replay, I suppose, and "realistically" how would you know that you needed Science! Rank 3 in order to get this particular dialog option?
(2) Being able to walk away from conversations ---- or, presumably, do other things, like pop some Mentats ---- might be advantageous if you discerned that you needed a higher INT/PER to get a dialog option, so you could pop some Mentats or quickly skim a book/magazine to boost your skill/stat/perk to a sufficient level to get the dialog option to appear / succeed.
In any event, my ol' Quicksave / Quickload buttons are going to get a hell of a workout because of Fallout 4 conversations....