Accommodating resistance equipment
They may have old injuries or just be so inflexible and immobile that the leverage disadvantage becomes too much when trying certain exercises with a full range of motion.They also may not have the core or stabilizer strength to do the exercise safely.Constant resistance devices are things like free weights or pulley machines where the wheel is round so it gives even resistance.One of the disadvantages of this type of equipment is that it does not correct for differences if biomechanical leverage changes.
Each one has different uses and has pros and cons depending on the user and purpose.
Also for everyday people, this type of resistance training has a disadvantage.
For deconditioned people or first time exercisers this may be dangerous even with light loads.
If the load is constant through the ROM, it's constant resistance.
Add a lobed cable swivle and it becomes variable resistance.