Lucks quite important, but SPECIAL generally isnt very important and doesn't really determine anything, tis all about Skills.
Since when?
All of them are needed at certain levels in order to unlock certain perks.
Strength provides carrying weight, which in hardcoe mode, can be very important for some weapons.
Perception provides your line of sight. Personally I don't find it too important with ED-E, but there are still good perks tied to this trait.
Endurance is how many hits you can take and how many implants you can get. Pretty self explainatory.
Charisma, ok, is perhaps not so important. Only a couple perks tied to it.
Intelligence, as it's been stated, gives you more skills.
Agility determines how quickly you reload and draw your weapon, and like Perception, has very useful perks tied to it.
And Luck determines your casino luck. 10 Luck basically gives you free money, whereas 1 luck means you won't get a dime. It also has other effects, of course.
If you truly think these have nothing to do with gameplay, then I'd love to see you do a gameplay with all of them set to 1.