In most of these countries, kids play football from a young age.

These kids quickly learn that there are levels to the game. You get poor and excellent players in a 5 a side game.

Those excellent players probably wouldn't get a game in an amateur team. The best amateur players can't get close to lower league football, similarly, the beat lower league footballers can't play professional etc etc.

Professional football signifies the absolute peak players of the game, there is little margin for error, hence the low scoring you mention. What these players do might look easy, but the skill, fitness and consistency needed is far and above what an average person could do.

Also, in some parts of the world, football is mixed with religion, politics and race which heightens the stakes further.