Airbnb employees get paid in stock. For many it may be as much as 40% of their total compensation. If the price drops, those employees are going to be very upset. The trading price matters very much.
Say, I join a public company. If they say they will pay me 500k USD worth of stocks, it generally means that I get 500k/(average share price of month, share price on stock offer date etc.) stocks subject to vesting cycle. Basically, I have fixed number of shares from that point and they appreciate or depreciate with the market.
I am assuming if AirBnB offered 500k USD of RSUs similarly and the RSU price was say 50. That means the person had 10k RSUs subject to vesting cycle. So, if the stock price is 120 now they have 1200k USD worth of stocks subject to vesting cycle.