As a general rule, Reacher is in peak physical condition and at the top of his game. Which doesn't make sense, because he's technically retired. But he's naturally built very strongly, spends his days wandering about the country, sees action every time a story comes up, and sometimes this is actually explicitly noted as not being enough.
At the end of Nothing To Lose, Reacher and his partner blow up the metal salvaging plant owned by the villain and his co-conspirators with their own bomb. It's poetic justice... until you consider that one of the side plots was the presence of a highly carcinogenic chemical and how small amounts of it are leeching into the water supply not to mention the main plotline that the villains were building a dirty bomb packed with depleted uranium. Congratulations, Reacher, for creating an environmental disaster site.
In Worth Dying For, the villains all coerce each other into sending their men to deal with Reacher's presence, with the threat of grisly violence on the villains themselves if their men fail. Their men fail, of course. So those threats are likely to be acted on before long.
Not that this will ruin their operation, or anything. The supply and demand for the product they were shipping are both overseas. Reacher's heroics will have fixed that one only very temporarily.