Free bet is useless. Even if you win, you're unable to withdraw the winning proceeds. So, why waste times to play free bets? Unless you just want to have fun and get acquainted with the platform.
Since I played gambling, the free bet I got did not disappoint me. There are some that I can turn into real money and some that I can't. If you think it's wasting time you are wrong, in fact this is very useful for people who want to get free money.