To be fair, the DisplayPort 2.0/2.1 standardisation process was riddled with delays and they ended up landing years after HDMI 2.1 did. It stands to reason that

To be fair, the DisplayPort 2.0/2.1 standardisation process was riddled with delays and they ended up landing years after HDMI 2.1 did. It stands to reason that hardware manufacturers picked up the earlier spec first.