I haven't read any of the books, but it sounds like they cast this guy properly. The quality of the writing varied almost from scene to scene. Sometimes it felt like a gritty action show that would be perfect for a streaming service; other times it felt like a hacky broadcast network show that would fill in the 10pm CST timeslot, right before the news; and still other times, it seemed like porn for women. The female lead was almost a Mary Sue, because she was tough and showed no fear, but that changed in later episodes and while she was scrappy, the writers were smart enough to remember she was 98 pounds soaking wet. Generic bad guy, straight from the 1980s TV shows by Glen A Larson, or from Roadhouse.
There wasn't enough comedy in there to make it as fun as a Marvel movie, but too much for it to go into really dark action places. There were some clunky, predictable and unneeded flashbacks, and I bet those will be gone in Season 2. And for the most part, Reacher seem like the Mary Sue here, perfect shape, perfect fighting, and can outsmart and out-punch any situation.
That said, the guy whooped some ass, and you could use the Reacher fight scenes as a clinic on how to practice to take out one or several henchmen in your everyday life.