Um, no. A common misconception. It may make you have bigger muscles, but it won’t get you fit per se. Strong does not equal fit. I think many people have a very bent idea of what fitness is.
Lifting weights won’t give you the fitness to ski for 8 hours non-stop. Won’t give you the fitness to run a marathon, or ride a century. Won’t give you the fitness to swim further than across the pool.
And don’t forget that gyms in Taiwan, like elsewhere, are generally little more than a well-planned way to part a sucker from their money.