You are paying for what the resort provides (pools/food/bars/entertainment), not where it is located. From what I could tell, most guests rarely venture outside the resort until it is time to fly home. The location is definitely not anything special or scenic. The neighboring beach is full of mostly dilapidated old resorts and condos. The best locations for a resort were built up a long time ago, so the resorts in the best spots are mostly quite old. New resorts typically get built on land no one wanted to use, and no amount of landscaping will change that once you venture beyond the property. This tends to be a reality almost everywhere I have been: you can choose a nice new resort on a crappy rocky beach or a 50-year-old block building on a nice white sand beach.

The sargassum is an issue all over the Caribbean and SE USA, as it stretches for 5k miles across the Atlantic Ocean, so you may want to be looking west to the Pacific Ocean to escape that mess (but then you need to contend with colder water and a proliferation of stinging jellyfish). I'm no expert on CUN, but I would venture to guess the best scenery/beaches are in more remote/less developed places to the south, including Tulum and south towards Chetumal. The same goes for sightseeing, as the only thing I could find in the vicinity of PDC is Xcaret and numerous cenotes. Personally, if I were to go back to this area, I would be looking at Cozumel, which has much better options for watersports/snorkeling and its own airport, making it possible to avoid the hellish traffic around CUN. Alternately, I would also consider flying to Chetumal and venturing no further north than to Tulum. I am not completely sure what the chief attraction of CUN/PDC is, but sightseeing and interesting beaches must not be high on the list.