Point-buy really makes sense in a party, where you don't want the other PCs to be overshadowed by the one PC whose player 'somehow' managed to roll three 18s and nothing under 14 (yes, those with a few years experience of PnP have all played with That Player). It gives a nice level playing field. We use the set stat array, which is similar (you allocate a preset set of numbers to your stats). That would also work for BG3 should the designers be able to implement it.
In addition, I generally have an idea what the character is going to be before I put pencil to paper (or, increasingly nowadays, finger to keyboard). If I want to play a Norse warrior with a Big Hammer, I'm going to very disappointed if I roll 6 for STR. Spread rolling is better, where you roll six sets of stats and then allocate them, but even this doesn't really ensure your hefty warrior is going to have anything more than slightly-above-average STR. Especially when the party wizard is stronger than you are.
My first ever AD&D character, a cleric back in 1980, found his class calling because we used the old method of rolling 3d6 in turn for each stat. I ended up with my best stat being WIS 13, and thus was a cleric. It sucked, especially as I also rolled 1hp, and I was not sorry when he was killed by orcs. Luckily I persevered with RPGs, but swiftly converted to Runequest which became the start of long and beautiful relationship with classless RPGs.
