If you really want to win at betting on sports or etc. You should know how to observe and be measure things. First look at the different statistics of each teams and find their strengths and weaknesses for you to be able to know if the team you are choosing has the potential to win against their opponent.
If you look at the Tier 1 and 2 teams the odds should be pretty fair and will give you a good indication on who will likely win. There are so many people looking at the big teams like PSG for example that I it will be very hard to find thing that everyone else missed. Since the football matches are back during the pandemic I started to bet only on fairly sure games where the risk of losing is fairly low. Sure the winning are low too but it's better than to lose money at the moment.
I think this is a good way to bet. You could keep doing that and see how profitable you are, then start increasing your bet and skills in the long run if you are profitable. I guess lots of sport bettors are more focused on prize than skill/knowledge, hence they take big financial risk and lose often.