I had to borrow a phone to set up a mobile hotspot.
It has the same speeds inside the wireguard tunnel as when I tested from my wired connection (250 kbps TCP, 170 kbps UDP).
The loss reported by iperf is dependent on the bandwidth that i test with. But as I increase bandwidth from the client the loss grows towards 100%.

I tried testing in reverse (sending from VPS to devices on different networks) with surprising results:

• TCP, wireguard: 5-10 mbps
• UDP, wireguard: 50 mbps
• TCP, no wireguard: 45 mbps
• UDP, no wireguard: 250 mbps (saturates download speed on client when compared to speedtest.net)