Question

why can’t rowers only perform dry land training

Answer 1

Rowing is a sport that requires strength as well as cardiorespiratory fitness to perform better.
A rower needs to perform dry land as well as water training.
Dry land training helps the rower gain strength and aerobic fitness through ergometry, cycling, jogging and resisted resisted exercises. Dry land training also helps the rower focus on different body parts through cross training.
Water training helps the rower to improve his technical skills through rowing practice and work upon his weaknesses. Water training will also give the rower a practical experience of the sport and prepare him for difficulties encountered during rowing. Water training also provides excellent cardiorespiratory and aerobic workout.
So a rower required dryland as well as water training to achieve aerobic fitness and strength and improve hus technical skills.