A lot of people say snakes don't need UVB because they eat whole prey, maybe that is so with nocturnal snakes. But I think that all reptiles benefit from UV, they get it when basking. All my reptiles have UVB, wasted money or not. 1 last point, if whole prey (including calcium) was sufficient then lizards would not require UV either, we put calcium on their bugs !!!!
You get snakes including pythons including Carpets spending their whole lives living in caves and not getting UV. Many reptiles never get exposure to UV, and being exposed to something naturally doesn't make it necessary or beneficial (parasites for example are a negative aspect of the environment, as are extreme weather events which kill a percentage of the population, as well as parasites, live prey which fights back, etc etc). Some aspects of the environment are neither harmful nor beneficial (you don't need to paint the ceiling of your lizard enclosures blue for example, even though they naturally live under a blue sky - they always get this but don't need it), and some are important.
Good husbandry does not at all mean replicating nature. Nature is a terrible environment which reptiles cope with, not do best with. To put it into some context, of all the offspring a female reptile produces in her lifetime, on average almost all die before maturing and only two successfully become adults and reproduce themselves. Only two - all the rest die before they have the chance. Wild reptiles are typically covered in parasites, scars and have nervous temperaments. Wild reptiles die from droughts, floods, heatwaves, cold winters and many other negative impacts. Heck, even humans which naturally get plenty of UV are constantly told about the dangers of natural UV exposure! Trying to provide something just because they get it in the natural world is not a good recipe for keeping animals happy and healthy - reptiles in our care typically do far better than wild reptiles, and so they should!
As for the 'whole prey' thing, that's never been a myth I have taken seriously and does not explain the biological mechanisms at work. I'd love to discuss it but it would take too long to type up the several pages necessary to explain it and no one would bother reading it, but 'whole prey' is not the explanation for why snakes don't need UV, and incidentally, I've kept lizards of a wide range of types for multiple consecutive generations without any UV, and experimenting with UV made no difference, but absolutely, supplements are necessary (and artificial UV doesn't mean you don't need supplements). This is too big a topic to get into properly here, but empirical evidence does show that in the context of a normal captive skink, gecko or monitor, UV is irrelevant but managing the diet is critically important, and this is perhaps where the 'whole prey' myth comes from. Just briefly, the big difference is that wild snakes eat exclusively whole animals, and this is what is done with captive reptiles, so it's all good. Wild lizards typically eat a wide range of feeds including fresh plants and invertebrates of a wide range which themselves have been eating a wide range of feeds including various fungi etc, and this variety is very difficult to replicate artificially, so we need to fortify their diet with the essential missing micronutrients, but simply adding UV to a normal unfortified captive diet does not prevent the problems.
No one makes money from telling you not to waste money on UV lamps, and plenty of people do make money from convincing you to use them, while people also earn social credit for advocating them. This being the case, the myth is likely to persist indefinitely. But, as an example, look at the people breeding monitors, skinks and geckoes on a large scale, for money, whose income relies on their animals being in good health and having high reproductive output - they do not use UV.
And again, illustrating the point that natural does not mean harmless, the global consensus view among health officials is for humans to stay out of the sun and not get the natural amount of sunlight. I actually don't agree with this advice, but it does clearly show that UV is harmful along with any benefits it provides, so if it's not providing benefits to some species, it's best not used, and without any doubt, the harm can outweigh the benefits in some cases, and this is especially likely with artificial UV sources which have varying spectral outputs (and if you want to believe the 'natural is best' myth, aritifical UV lamps never mimic the natural light spectrum).
