Scan both sites
The free scan works on any public website, and you do not need to own it. It asks for the web address and your email, reads 5 pages, and allows one free scan per email every 30 days.
Start with your own site. To put a competitor's public site beside it, run a paid scan of that site. Both results use the same five areas: Technical Foundations, Schema and Structured Data, Semantic Architecture, AI Readability, and Authority and Operational Discipline. When a competitor scores higher in an area, open that area on your own report and read the findings listed there.