Couple of potential ideas off the top of my head:

- continued rise in remote jobs means larger percentage reports from lower cost-of-living areas, pulling down the average.

- pull-back in tech markets reduces the dollar-denominated equity piece of compensation

- balance of power is shifting back to employers given current market sentiments

These are aggregate metrics. As such, individuals may have seen their salaries stay the same or even go up, but if the employees at the top of the pay scale are removed (layed off, or even a simple selection bias in the dataset), the median will still drop.