Ruy Lopez: Friend or Foul?

I sat down one day with my set and set up the Ruy Lopez position. The basic position 1. e4 e5 2. nf3 nc5 3. bb5. I used to play this, and I asked myself, “What do I gain by playing bb5?” And I answered myself, “Three things. 1. Control over the a4 square. That does not help you at all. 2. You can now castle, but that can also be reached through the Italian Game. (Guico Piano.) And thirdly, you are contesting the e5 square. Some later advantages are 1. You will get a lot of space. (Via c3 and d4, also reachable through the Italian game.) 2. The bishop becomes active on the a2-g8 diagonal(again, reachable through Italian game, but most notably the Evans Gambit.) So why do so many Grandmasters play it with regular use? Maurice Ashley suggested it to me, and for a long time I played it, and it is without a doubt a good opening: FInd one master level player who has not played it. I just think it is very… interesting. Please leave your opinion. Thanks.