Windows PCs had (have?) that Internet connection sharing feature for a long time. It was really just a checkbox to enable NAT too.
Sometimes I think combining a firewall/router/switch/AP/file server/etc into a device called a "router" really confuses people. Even people who should know better.
You can do a lot of routing on a $70 Mikrotik, although they might not be "easy".
Too bad I can't fill it with old spinning rust.
Everyone has a starting point, starting with soemone has lying around is one thing.. the quicker they can get going the more they can get to leveraging the real power in most devices.