Uber or Lyft marketing is made in such a way that they would profit immediately if they don’t invest in other growth areas , to make it appear like another amazon or Facebook. Which metric tells us whether company would be immediately profitable if they don’t do growth investment ?
Look at gross profit or remove cap ex from net income.
Look at CAC vs. CLV and marketing expense related metrics. Are acquisition costs increasing or decreasing, and is it happening faster than revenue and/or contribution margin? If you can get per-market metrics those are useful too.
One could look at per market profitability.