We love Riviera Maya and first visited the area in 1980
We try to return every 2 years
Yes there has been a lot of development around Tulum that is not pretty but the ruins are still worth a visit and the beach to the south is nice
PDC is busy but still enjoyable
While the area has developed you can still enjoy some terrific place s like TANKAH with its lagoon and beach area. Also love Akumal,Aktun Chen cave,many cenotes,Xpu-Ha,EkBalam for an out of the way Mayan experience. Always spend some time in Puerto Morelos as snorkeling is great and town is fun. Try a trip to Isla Mujeres etc etc etc
There is so much to do and that's why its a great place to visit. Having been to many Carib islands, Hawaii etc it is probably our favorite place. Rent a car and get good maps and you will have a great time!