Here the problem is not that Amazon asks for compulsory GST registration without any purpose, they are correct in asking for GST registration because as per section 24 of GST act any person providing inter state supplies will have to compulsorily get GST registration irrespective of its turnover. Thus even if you sell it via your own website you need to get GST registration if you are going to provide interstate supplies irrespective of your turnover.
People come online to sell their products in whole of India therefore Amazon is not wrong in asking you to get registration.
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