Did you re-read this before posting?
"PS2 is selling power because you want to be good for every situation that arises, but in LoL it's ok to scrub it out with just a carry and one rune set"
How is that a fair comparison?Your one chosen champion and rune setup is *not* sufficient past facerolling for lulz in LoL, starting with the obvious fact that it might be banned or picked before it's your turn, and that's assuming you pick it always with no regard to the balance or meta or previous picks of both teams. "I take alistair solo mid or I feed" statements come to mind. If that's ok then always going infiltrator with smg and skulking for afk victims is valid also. If you apply the same expectations you have for your PS2 situation to LoL then you need a full stable of champs for flexible role selection and counter-picking depending on how the champ selection goes. And then you need to buy or farm IP, same choice you have in PS2 when you want to able to have every possible loadout available: Buy or farm certs.
Ignoring the obvious differences between open world MMO gameplay and 5 vs 5 arena gameplay, I consider the advancement setups similar (and well done in both, sure beats most other F2P games). In both LoL and PS2 you can max one setup/role/champ fairly fast and expand your arsenal while mostly playing that, but you need to branch out and learn the other parts of the game to become a greater asset to your team in different situations. Also in both LoL and PS2 you have balance changes and fotm setups/team combinations that have great influence on how/what you get to do effectively (you can still do other shit you're just not really contributing then).
P.S: PS1 cert system was certainly more freeform with your armor choice dictating much of your loadout, but I'd say that is 'different' and not more or less powerful/P2W. PS2 is a different game then PS1 though, this would be like complaining that WC3 had heroes and SC2 doesnt and whats up with that, just because they are otherwise similar games that share a genre and developer. That said it would be nice if some things in PS2 were more like PS1 actually and they seem to move that way slowly, wru continent links/locks.