With v5.0.1 of iw, every command gives the same result as in this example:

finger@linux-n6zm:~/rtl8723bu> iw dev
Usage:  iw [options] command
Options:
        --debug         enable netlink debugging
        --version       show version (5.0.1)
Commands:

Commands that use the netdev ('dev') can also be given the
'wdev' instead to identify the device.

You can omit the 'phy' or 'dev' if the identification is unique,
e.g. "iw wlan0 info" or "iw phy0 info". (Don't when scripting.)

Do NOT screenscrape this tool, we don't consider its output stable.

finger@linux-n6zm:~/rtl8723bu> 

After downgrading to v4.9 from Leap 15.1, the correct result is obtained:

finger@linux-n6zm:~/rtl8723bu> iw dev
phy#0
        Interface wls1
                ifindex 3
                wdev 0x1
                addr 46:51:17:3a:39:09
                type managed
                txpower 20.00 dBm
finger@linux-n6zm:~/rtl8723bu>