The act was primarily written to target tie-in service for profit, which is not the primary motivation of companies making consumer electronics that are difficult to service today; they want it to be replaced, not repaired. It was effective for that purpose, and continues to be effective when enforced.
Moss isn’t a panacea. It does not cover making devices impossible to service in a cost-effective manner, availability of parts, serialization, or other anti-repair practices. It’s just about warranties.