Yes, it is. When you reply to an IP address, you don't magically punch a hole through the entire network to the user's physical location.
You send a packet to your ISP with an address on top. That packet physically travels to your nearest exchange and then the network figures out how to route it to the recipient's real location.
In addition, the recipient's IP address tells you nothing about who or where they are. It's fundamentally un-knowable from the sender's perspective, no matter what the UK wants you to think. IP addresses are not evidence of physical location.
When you receive a packet, there is no way to know where in the world it came from or where it wants to go. It's just a number. You can make guesses but it's still just reading tea leaves.
To believe that IP geolocation is in any way reliable is a gross misunderstanding of TCP/IP and networks in general.
