[1] It's developed by Fraunhofer IIS and Ericsson as the successor of the SBC codec.
[2] LC3 provides higher audio quality and better packet loss concealment than SBC, G.722 and Opus, according to subjective testing by the Bluetooth Special Interest Group and ETSI.
[3][4][5] The conclusion regarding Opus is disputed as the test only included speech audio, but the comparison was made to version 1.1.4 of the reference Opus encoder, using complexity level 0 at 32 kbps and relying on CELT (general audio) instead of the FEC-capable SILK (speech); the test also did not take into account the newer version 1.2 of the Opus encoder released in 2017, where significant improvements were made to low bitrate streams.
[5] Supported systems: LC3plus High Resolution mode is a codec defined by ETSI and is not compatible with the LC3 defined by Bluetooth SIG.
The ETSI implementation of LC3plus is source-available software, subject to a ETSI Intellectual Property Rights Policy and the usual patent restrictions.