My entire family uses different Moto G versions. I have the G4, one of my sisters has a G3, and my parents and my other sister have G1s. They just seem to work and are very good first-time smartphones for my parents. It has been several years since they got them, and I don't even have to provide technical support. Honestly, I see very little reason to unlock the phone.

It wasn't mandatory mostly because Motorola was commited to provide the latest Android which ensures you'll never be out of a new feature. But G1 aren't supported anymore, if today's Google conf apps aren't Lollipop friendly you're stuck with unlocking.