Stretching tools and rowing machines both support fitness routines, but they solve very different problems. Stretching tools help a person control position, range, tension, and support during mobility work. Rowing machines create repeated cardio and pulling effort through a sliding seat, handle, and resistance system.
The difference matters because one category is mainly about assisted mobility and recovery, while the other is about conditioning. A strap, block, wheel, or mobility stick should not be judged like a cardio machine, and a rower should not be expected to replace targeted stretching support.