I don't know how Zimbabwean citizens will react to such a law, but if you ask me, it's not really right and proper.
A similar law has already been implemented in other countries like the USA, where the rate is even higher than 10%, and gamblers have no choice but to follow it. However, I believe there’s always a way to avoid paying it, especially since it’s not a tax directly withheld by casinos or sportsbooks.
In Zimbabwe, I’m pretty sure the implementation won’t be perfect. If gamblers want to avoid paying, the best option might be to use sportsbooks that aren’t regulated by the government. That way, the authorities won’t know whether we’re winning or not.