“The Buddha treated religion as a personal matter. He demarcated religion from secular power and accepted that each should have its own priorities and values. The turning of Buddhism into the Lankan state religion unbalanced this equation.”
Himal SouthasianSri Lankan Buddhists believe that the Buddha’s teaching exists in its purest form only in their land. Yet caste is the basic organising principle of the Sri Lankan sangha. Read the piece by Tisaranee Gunasekara to know more: https://www.himalmag.com/sri-lanka-sinhala-buddhism-history-hemarathana/