F. Brawlers have some difficulty with gearing, but in general you have a few more options for gear choice than other classes. In consideration for end-game, F. Brawlers can take on a support-like role with their stuns, holds, and Heaven’t Net to offset a lack of gear.
My F. Brawler is decently geared, but I am nowhere close to being as geared as some of the other people here, so I’ll defer to their opinions when it comes to end game damage. They have been discussing it for a while now and you can look back through this thread to get an idea of where F. Brawlers stand.
If it’s your first character ever, yes, F. Brawlers are a bad first class. Though this is the case for nearly every other subclass, so it’s not much of an issue. F. Brawlers don’t really have any room-clearing skills until after 1st awakening, but again that’s kind of the case for many other subclasses.
Early on, you’ll realize that Sand Splash is stupidly strong, and it stays stupidly strong all the way until Power Station (level 85). I highly recommend maxing it as you level, but just know that it falls off very quickly after 85.