First two links are Go, so not relevant to client-side.
Third link is also server-side, but since it's NodeJS it's at least close enough / more relevant to client-side perf.
Here's the benchmark from the third link:
benchmark time (avg) (min … max)
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encode-JSON 342.37 µs/iter (311.93 µs … 1.19 ms)
decode-JSON 435.9 µs/iter (384.44 µs … 1.41 ms)
encode-PB 946.43 µs/iter (777.38 µs … 3.13 ms)
decode-PB 770.79 µs/iter (688.99 µs … 1.78 ms)
encode-PBJS 696.75 µs/iter (618.43 µs … 2.43 ms)
decode-PBJS 455.36 µs/iter (413.66 µs … 1.09 ms)