Black Desert, from what I understand, is purely pvp and dicking around: doing fishing, transporting goods and stuff like that since it's a sandbox. No real dungeons or pve.
Also, I believe dnotel might have the perspective from someone that has already played Blade and Soul from other regions. It's true that if you rush to max level in a few days and start to do the end game dungeons, you will end up getting max gear pretty fast after that especially if you invest several hours every day.
However, as a completely new player and especially if you like going around the world trying to see a lot of aspects of the game (I include getting different outfits and weapon skins in that) it will last you a good while. You will need more time to figure out stuff anyway. Keep in mind that you can level new classes in order to learn their skills and mechanics as well (which older player already know). You can also always try to challenge yourself and try to solo some of the dungeons.
So in my opinion, there is enough content if you want there to be to last you a while. Especially since it will be f2p unlike Black Desert online.
If you do end up playing the game, be sure to give 1v1 pvp a go. Just like traditional fighting games, you can just jump in and button mash your way into the fight and still enjoy it because the combat is so fun.
If you like PVE, Black Desert is not the game for you. BDO is a sandbox game and is only really good for exploring, playing the economy, and PVP. I played the Korean version and it was a super grindfest with the most basic questing of "go here and kill x of these."
BDO is more pvp, guild war type thing at end game. If you don't want to pvp in it there is the whole economic part. Think of it like a fantasy character based EvE online. In both, there is pve stuff, but that's not really the reason to play either.
Here, once you hit 45 you will grind dungeons over and over an over if you don't pvp. Even when they make the cap 50 you will do the same. Not even that interesting dungeons, especially once you've done them dozens of times each.
This is from someone who enjoys each for what they are, btw.