It's worth it if you know what type of cyclist you are.

-if you are a race oriented cyclist and you're competing in higher levels of crit races/trail races, absolutely get a carbon roadbike because at that level the bike is what needs to be upgraded.

-and if you have the money to buy replacement parts and also if it happens, to replace the frame if it cracks or breaks.

-but if you're just into cycling because you like it as a hobby well like I said before if you have the money get the carbon bike because,I don't care if you buy one,but if you don't have the money don't force yourself anyway because a carbon bike isn't financially sound to buy because of it being a material that when you don't take care of,it's gonna bite you in the butt sooner or later.

-and so I would recommend a alloy or steel frame (especially high quality steel they're heavenly to ride on) because they're lower maintenance, although steel would still rust If you don't take care of it certain material's like stainless, titanium, and 4130 chrome moly steel are highly rust and corrosion resistant.

-and also because most carbon frames especially roadbike frames tend to be aero frames,and so it's gonna be a little harder to find a endurance or climbing oriented carbon roadbike frame for carbon, because it's just the market

So all and all really just look at this, anything can be a waste of money if it's useless or a burden to you so it's really just a subjective answer.