Is contract testing with Pact worth the setup cost for a 2-team API boundary?

We have two teams: one owns a user service (Python/FastAPI), one owns a frontend (Next.js). The user service API is the boundary. I've been reading about Pact for consumer-driven contract testing. The concept makes sense but the setup looks significant — Pact broker, CI integration on both sides, keeping pacts in sync. For just two teams sharing one API, is Pact overkill? Would maintaining an OpenAPI spec and generating both server and client types from it give us 80% of the value with 20% of the overhead? Curious if anyone has done both and can compare.