Tether will discontinue USDT support on Omni Layer, its original issuance network, due to steep declines in usage and the emergence of competing blockchains

Quotes that support claims

Omni was the first transport layer for USDT when it was launched in 2014. Omni was an early scaling layer for Bitcoin, but its usage declined as competitors emerged.

Tether will discontinue USDT support on Omni, marking the end of its original issuance layer. Despite processing millions in its prime, Omni has seen steep usage declines.