SoftBank Internet is a joke

Kind of a rant, but does anyone else use SoftBank in Yokosuka area and hate it too?

I thought moving to Japan would give me better internet speeds and service than U.S. but it’s just as bad and maybe worse.

Firstly, I am paying for SoftBank Hikari, which is advertised as 10 GIGABIT speeds. However, I am getting barely 250 Mbps on 5 GHz wifi and 800 Mbps over CAT 6A LAN. The speed discrepancy is appalling and unacceptable.

Not to mention you HAVE to use the Hikari rental router and can’t use your own one according to SoftBank support. Something US cable companies allowed.

Why am I paying for “SUPER FAST” 10 GIGABIT internet if I am not even getting 5% of the advertised speed. This is a joke and makes American ISPs look superior in every way.

This should be considered false advertising and unacceptable.

Edit: Yes I called SoftBank and they just said this is normal and there’s “nothing we can do.“

Edit 2: motherboard is ASUS Z790 GAMING WIFI7

Edit 3: Tried replacing SoftBank router using “Nighthawk WiFi 7 Router RS500, 12Gbps.” Didn’t have any internet connection and SoftBank said third party routers won’t work.