BARCELONA, Spain—Somewhat unusually for a newer phone, the Moto G5 isn’t a flat-out better phone than the Moto G4 in every respect. It’s just… different. The biggest upgrade is in the Moto G5’s build.

We’ve documented the decline of Motorola under Lenovo extensively. We still liked the phones, which had probably been developed mostly under Google’s ownership anyway, but in 2015 we started to see ...