I think that's the myth promoted by his opponents, to win the 1980 election and of course to demonize all Democrats and other enemies.

But forget all that and examine it on the merits: As a start, he inherited the post-Vietname military, a shambles already, OPEC embargos, Iran, an America that had lost great credibility in Vietnam. He did Camp David, the most successful and effective security action in the Mideast to this day; began deregulation (yes it was him, not Reagan); put Paul Volcker in the Fed and signed the relevant legislation to get inflation under control; implemented the new all-volunteer military; was right about energy policy, ...