Cycling, in my opinion, is worthwhile or not depending on what you want out of it.

In my opinion "cardio" or developing energy systems is movment specific to a large degree. An extremely well conditioned distance cyclist will not have equally preportionate conditioning when running or rowing or fighting. One example is holding pads for a triathelte - one round he was pooped. Now to a degree he'll be more relaxed running etc than kicking and this will play a factor but I think it is also movment specific. Also cycling and running, even with sprints etc or not as explosive or start and stop as kicking and punching and the muscles are not conditioned nor is the energy system conditioned to facilitate that as much as kicking and punching will. IMO&E

Consideration of postural weaknesses might be worth it. If you have tight hip flexors and your hunched all the time it will only make things worse without some counter strengthening/stretching etc

IF you decide to ride a bike for any reason a recomendation is to keep your tongue on the roof of your mouth. Cycling tends to separate the linking of the right and left hemospheres of the brain (not sure why exactly - I think it might be discussed in "Your Body Doesn't Lie" - Diamond... the tongue in its physiological rest position helps keep the right and left hemospheres working together.

Swallow, feel where your tongue goes and that is the tongues natural resting spot when not being used - eat, sing kiss etc. Over a short period of time if you practice this the body will remember the tongues natural resting spot and will automatically go there.

side notes on tongues natural resting position

some muscles in the neck only activate when the tongue is in its natural resting position - that means your neck is stronger, as more muscles will be used, when the tongue is on the roof of your mouth - this is huge in wrestling, getting hit and doing explosive and power moves

two main Chinese meridians also connect when the tongue is on the roof of your mouth and the energy flows are strongly affected in good ways, affecting EVERYTHING to do with mental, emotional and physical health.

IMO&E