This seems to depend on kernel version. On one F30 system it works:
[root@yoga ryniker]# uname -r
5.0.17-300.fc30.x86_64
[root@yoga ryniker]# ls -l /sys/kernel/debug/usb/devices
-r--r--r--. 1 root root 0 May 30 09:59 /sys/kernel/debug/usb/devices
[root@yoga ryniker]# cat /sys/kernel/debug/usb/devices
T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 2
B: Alloc= 0/800 us ( 0%), #Int= 0, #Iso= 0
D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1d6b ProdID=0002 Rev= 5.00
S: Manufacturer=Linux 5.0.17-300.fc30.x86_64 ehci_hcd
S: Product=EHCI Host Controller
S: SerialNumber=0000:00:1d.0
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 4 Ivl=256ms
T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=480 MxCh= 8
D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=01 MxPS=64 #Cfgs= 1
P: Vendor=8087 ProdID=8001 Rev= 0.03
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 2 Ivl=256ms
...
while on another, with the latest (non-test) kernel, it fails:
[root@puget ryniker]# uname -r
5.1.6-300.fc30.x86_64
[root@puget ryniker]# ls -l /sys/kernel/debug/usb/devices
-r--r--r--. 1 root root 0 Jun 6 08:11 /sys/kernel/debug/usb/devices
[root@puget ryniker]# cat /sys/kernel/debug/usb/devices
cat: /sys/kernel/debug/usb/devices: Operation not permitted