Many TODOs (the majority in code bases I've worked on that had them) do not require any action, they are annotations to the code base about future potential development or research. Addressing the TODO, either by removal or implementation, could be deferred indefinitely with no consequences and often are. These aren't things that need to be fixed per se. For example, I've seen TODOs widely used to document optimization or generalization opportunities in the code base.

You do not want to pollute your ticketing system with myriad TODOs. They are not meaningfully actionable and they tend to require very local code context so it is easier to understand them as code annotations.