I think, now major reason of tyres vendors switching to, and selling smuggled tires is; inflation, and deteriorating economic conditions.
Like everything else, tyres have also gone extremely expensive, and beyond the reach of masses. So, it seems very less people are interested in genuine import tyres, as their prices are huge. 2ndly, profit margins are less in genuine import tyres, so vendors are also switching towards smuggled tyres.
For general public: Smuggled tyres are slightly cheaper.
For shopkeepers: Cheaper tyres comparatively, as well as huge profit margins.
A win-win situation for all.