Due to some loot despawning/only spawning under certain conditions, following this route through downtown Seattle allows you to collect everything** available on Grounded mode. I had to do coffee shop twice because I did this section in two sittings and the game's checkpoint system is... a thing. **I leave a couple of things in the upper courthouse as it typically takes more resources to kill the infected than you can collect there. Save the axe in the fire truck til the end so that you can use it if necessary at the Serevena hotel.