Perhaps it depends on the nature of the tech-debt. A lot of the software we create has consequences beyond a paticular codebase.

Published APIs cannot be changed without causing friction on the client's end, which may not be under our control. Even if the API is properly versioned, users will be unhappy if they are asked to adopt a completely changed version of the API on a regular basis.

Data that was created according to a previous version of the data model continues to exist in various places and may not be easy to migrate.

User interfaces cannot be radically changed too frequently without confusing the hell out of human users.