Is it just me or....
 

Is it just me or do Driftwood Island and Isla Congrejos have the same layout? I just notcied this... the only difference to me is the Ship and Trees on Driftwood and the Graves on Congrejos, but am I right or are they different?

Yes, they do. Same with the island you reach via doing the PvP glitch incorrectly.

a lot of the forests have the same layout too.

This has been the way of the non-town islands and caves for as long as I can remember, at least until they changed up the caves in the update last August or September. You get those few other attractions but besides that, EXACTLY the same.

But, in the future I think POTCO may change this and give a different look to every island and building. They changed the caves, why not change the other islands?

They use the same models for a lot of things. Even on the Black Pearl island, every fort is identical to the Kingshead, Padres, or Port Royal forts.

I think that there is a small difference... dont know what, but they are quite similar.