Man I hate when people ask that question, is it worth it ?
But for who ? We dont know you, we arent friends, we know nothing about you, how could we know if it's worth it for you ?
For me, yeah sure it's worth it , you can control your braking power better and even if GT is a simcade, you're not just smashing the brake at 100% and release it (or at least you dont if you are interest in being fast and getting better), you sometimes have to apply a certain power, for example when you cant break in a straight line and for that lc does help. I also play other sim like AC so yeah. And for F1 it's definitely worth it if you plan on running it without abs.
But it's hard to tell if it's worth it for you, 200 bucks is quite a lot for some people and nearly nothing for others. We all have different life situation, married, single, kids, etc.. so again it's hard to tell if it's worth or not. For me it is but then again 200 euro or usd isnt that much for me. My shoes usually cost me more than that and I have quite a lot of them.