There's little point in having attribute scores at all if you can just set them all to 16 or 18, even in single player. All characters will have the same stats.
Rolling is also a bit questionable if you can roll as many times as you want. And you can't really control that in a video game. Unless it's multiplayer and everyone creates their characters at the same time and only gets one roll. Or two rolls, i.e. advantage in character creation to avoid super low unlucky stats.
Point buy just makes the most sense in many ways.
I agree that sticking with point buy helps make sure a character isn’t wildly unbalanced and has a mix of manageable strengths and weaknesses. I like it as someone inexperienced in 5e, as it helps me make characters that work without being OP. Though I appreciate that more experienced players might find it restrictive and boring, I do think its accessibility means that point buy should probably be the default option, with players having to manually select standard array, dice roll, or free selection if they want to choose their stats another way.
But if folk use multiple rolls or free entry to play a character with all maxed stats in single player then it's no skin off my nose. And the fact that someone might skew their game in that way doesn't seem to be a reason not to let others who might like to determine their stats by, eg, physical dice rolls, enter their stats manually if there's demand for that.
