The so-called reuse is just that the boss sees that the ability of employees can create more wealth for them before putting them in a more important position.
Therefore, whether the company has achieved employees or employees have achieved the company, I think this is a mutual achievement, and no one can do without anyone.
Of course, the resources of employees and bosses are of course unequal. Two-legged employees are easy to find, and there are not many bosses with two legs, especially good bosses. Therefore, if there is an opportunity to be reported and reused, you must seize it.
If the boss gives you extra work to study and train, as long as it can improve your ability and level and not affect your personal life and health, then you can stick to it and see what better arrangements the boss has. If you find that the boss is just squeezing your personal value, then leave as soon as possible.