Conversion rate is the universal denominator metric of growth. Every funnel step has one: visit-to-sign-up, sign-up-to-activation, free-to-paid, lead-to-deal. Improving conversion at any step amplifies everything downstream.
The instinct to compare conversion rates across companies is usually a mistake, definitions, channel mixes, and audience quality vary too much. The useful comparison is your own conversion rate against your own historical baseline.