Does macOS 10.13 on macbook pro 2017 support VP8/VP9/AV1 hardware acceleration?
For AV1, no. The only dedicated hardware decoding for AV1 is in NVIDIA's latest GPUs, the 3000 series, Intel's 11th gen chips, and AMD's RDNA2 GPUs.
According to this discussion, VP9 hardware decoding is available. On Chrome, check chrome://flags/ to see if "VideoToolbox VP9 Decoding" is enabled.