Why is the 5 GHz amateur radio band seldom used?

Interestingly, 5 GHz band is also 5 cm band. According to one source, the allocation in 5 cm band for radio amateurs in India is 5725–5840 MHz or 5.725–5.840 GHz. For quite some time, I have been wondering why I have never heard of any amateur radio operations in this band. Even from abroad, where GHz range amateur radio operations are often reported on the social media platform X, I do not recall seeing 5 GHz activity. Incidentally, today morning I read about 122 GHz activity from Europe, on X. Important reason may be that 5cm band is very near the ISM band for unlicensed Industrial, Scientific and Medical use, including Wi-Fi, which is heavily congested. Moreover, 5cm is not a primary amateur radio band and being a secondary allocation, any interference from other services has to be tolerated. Amateur operators should not cause interference to the primary users of the band either.

Equipment for Super High Frequency or SHF band to which 5 cm belongs, require more complex and expensive equipment. Specialized antenna systems are also needed, increasing the barrier to entry to this band. Being line of sight propagation, range is also lower for the 5 cm band, unlike lower bands. Absorption by rain, concrete, masonry and even human body can make signals weaker in densely populated regions making communication difficult. In this context, it may be noted that 5 GHz is probably the lowest band for which rain scatter contacts are considered, though the popular band for rain scatter QSO is 10 GHz band. It has been mentioned that in addition to the 10 GHz primary science patch antenna and radio, CatSat has a 5 GHz patch antenna that will enable the spacecraft to operate for limited periods of time as a linear transponder. It will be possible for radio amateurs based on Earth to communicate through the transponder when it is enabled.