but why would they use the much riskier ATGM? it is more mass per munition, shorter range and requires line of sight. harder to smuggle and transport, riskier to use.
that would suggest ideologically motivated operators who accept additional risk.
Well, they had similar attacks during last year, as well as in 2010s(both with spikes, remote controlled turrets and kill teams on site).
IMHO the answer is simple: Iran is big, country with very rough terrain and enough insurgency/resistance problems. They just always could, and activated their existing network. Which worked just fine, though of course it limits the tempo of such operations to whatever can bring/bribe its way through.
Ukraine being this drone-minded is sort of global (forced) exception, other militaries adjust slower. Note that last year, most effective hezbollah precision attacks were also through Almas(i.e. Iranian spike-sr), not by FPVs.