byte[] generated almost 2GB worth of garbage during 30sec period of collecting profile data.
AFAICT after a quick look: this can be reduced if the connector could avoid Arrays.copyOf..() in PgProtoMessageDecoder etc.

grep -rI copyOf | grep byte
gives a list of the following suspects:
debezium-connector-postgres/src/main/java/io/debezium/connector/postgresql/connection/wal2json/StreamingWal2JsonMessageDecoder.java
debezium-connector-postgres/src/main/java/io/debezium/connector/postgresql/connection/wal2json/NonStreamingWal2JsonMessageDecoder.java
debezium-connector-postgres/src/main/java/io/debezium/connector/postgresql/connection/pgoutput/PgOutputMessageDecoder.java
debezium-connector-postgres/src/main/java/io/debezium/connector/postgresql/connection/pgproto/PgProtoMessageDecoder.java

See