Depends what you want to do at the beach. If you want to play around in the water, many of Bali's beaches are too dangerous much of the year for most average to poor swimmers to do that. Those good surfing conditions usually mean "beware" to swimmers. Some of the safer beaches as at Nusa Dua or Sanur, are too close to sewage runoff and water quality is ugh. I saw many Bali beaches are often not kept well (as in cleaned up, or get littered with rubbish). In my observations, the locals are the most guilty parties in the litter problem. That's a problem all over SE Asia, but Bali is such a small island that maybe the problem just seems more magnified there. Other places in Bali can be scenic but no beach to speak of any more due to erosion or commercial activities degrading it, or beach is rocky and more volcanic not sandy. Which has its merits for some but is not a classic "beachy" scene. As for ogling the "beautiful people" well I didn't see that many wandering around the beaches of Bali but maybe I just hit a stretch of off-days.

As for SE Asia, Thailand has plenty of better quality beaches, even parts of Malaysia or Vietnam or Philippines.