Like Ericsson and Alcatel, Nokia originally only built the phones to sell the infrastructure.

They pushed devices with new telecom features into the market to create the benefit for carriers to buy new infrastructure, e.g. "with this new revision of GSM, devices can negotiate the polling period with the network to double the battery runtime. But only if you have the infra to actually answer the device."

Citation needed. Nokia Networks and Nokia Mobile Phones (NMP) were run like entirely separate kingdoms within Nokia and their conflicts were legendary.

It's often forgotten that Microsoft didn't buy "Nokia", they bought the NMP division, and the Networks bit is alive and kicking to this day.