Mind there is also a BIG difference in SPECIAL and perk relation from FO1-2 and FO3/NV. Perk system here streamlined the whole experience, gave it less tweaking and tinkering with what and how things can be done and approached with your character. It opened a lot of weight and possibility to what you character can do and when. Simply nearly every single skill had a check (save for perhaps melee weapons and energy weapons, I don't recall one for those). In New Vegas this was brought back (since it was mostly lacking impact in FO3), you had your special checks, speech checks, but you also had repair checks, medicine checks, survivalist checks. Being able to modify various means for this with drugs, clothing and whatnot helped strategically how you planned to get gear items and whatever. Old fallout games had lots of instances (like joining Mordinos needed STR of 6), or sleeping with Bishop's wife needed either STR or CH of 6. Some checks needed one thing or another, not just 'take a perk to pass the check'. Speech was dependant on both charisma and your speech skill. In this example alone it gave you a different sort of feel for combat and how you went about it. Having 3 guys in power armor and geared up with M72,G11E or super sledge really helped a LOT.

For each 2 points you could have an extra companion.

In FO2 for example charisma gave you means of recruiting more people pending what your stat in it was. SPECIAL directly influenced how you got perks, it helped with some of the skill modifiers but it also had derived statistics which were important.

In older fallout games you had three parts to your character. It simply removed depth and choice in approaching problems and how you build your character.

Fallout 4 skill points mod