ant-libp2p-plaintext is used at run time in 2 crates (of which 1 optionally). It's used only as a dev dependency in 2 crates.

Depender (with downloads and own rev deps) ant-libp2p-plaintext version
140 1 ant-libp2p-swarm-test ^0.42.0
140 ant-libp2p optional ^0.42.0
160 3 ant-libp2p-relay dev ^0.42.0
150 2 ant-libp2p-dcutr dev ^0.42.0