Pokemon Go is not a task-oriented game until now, but with the latest update it seems that the game has been reshaped.
All players actually play Pokemon Go in a different way. Some of them like to fight in the Gyms, while the only goal is to catch different pokemon and complete pokedex. The fact that there was no task system in the game allowed such different modes of play. However, thanks to the new task system, playing the game seems to make it both more enjoyable and more likely to play the game.
You do not need to change how you play the game. Indeed, you do not have to perform every task. You can have it by fulfilling the task you want from the task list and you can choose the most appropriate task for your own game style on the continuously updated list. For larger rewarded and challenging tasks, you will need to visit the pokestoles. However, all pokestoplos give the same task within the same day. So if you choose to do the pokestop task, it will not be useful to look for different pokestop prizes with different degrees of convenience because you will encounter the same task in every pokestop you go.
The advantage of this situation is the possibility to fight in crowded groups. You can complete a single task with other players in your pokestop quests. The benefits of playing the game in crowded teams were revealed in the legendary pokemon fights made in the Gyms, and it is actually very enjoyable to play crowds. Moreover, if you perform a task without interruption for seven days, you also have a chance to win a legendary Pokemon.