Throwing out the ISS before we have at least part of a replacement in orbit is an excellent way to risk failing to have a space station completely.

I agree. We are not doing that though. Haven-1 is scheduled to launch NET 2025, the Axiom orbital segment is NET 2026, Orbital Reef is targeting 2027, and Starlab is targeting 2028. Even if these schedules slip a couple years, they would still be ready in time for the ISS deorbit in (or after) 2030.