The 10.0.0.0/8 block gives 16.7 million private addresses, so it is the range of choice for large organisations and for ISPs that ship gateways with 10.0.0.1 as the admin address. Xfinity customers log in at http://10.0.0.1.
Because 10.x.x.x is also used inside many VPN and container networks (Docker often picks 172.17.x.x, Kubernetes clusters frequently use 10.x), address overlap is a common cause of "VPN connected but can't reach the office" problems.