Beam search has been used in ASR extensively over the years in far too many works to cite, and in strong, recent results and systems including wav2vec 2.0 and NVIDIA's NeMo.
Why beam search?
Beam search remains a fast competitor to heavier-weight decoding approaches such as RNN-Transducer that Google has invested in putting on-device and has shown strong results with on common benchmarks. Autoregressive text models at scale can benefit from beam search as well. Among other things, beam search gives: