I love this question, nice one admin.

Well for me I think football should be a journey, a player should prove himself or herself in different clubs and country. My reason for this is that every league or country have different style of play and tactics they used. A player should show that they can adapt anywhere they go, that's what distinguishes a versatile player from just a player.

For example the italian type of football is mostly defensive and being able to convert the few opportunity they have. While the English style is more of a balanced, physical, tactical teamwork. The german football is mostly all attack, high pressing, goal scoring tactics.

We have seen lots of good players, doing fantastic leave their clubs or league and move to another league, only for them to struggle the the demand of the new league. Some of them adapt with time, while some goes back to their former league. A good Example is Memphis Delay who left lyon as their star player and came to manchester united with high expectations, only for him to end up as a flop in the premier league. So he has to go back to his french league to pick is form back. Another example is Angel Di Maria.
Another example is Cristiano Ronaldo who left his clubs and always do well in all the clubs and league he goes.

So for me I don't really think a player needs to dedicate is career to a team. If I was a player I wouldn't dedicate my whole career to a team, although the team will always mean a lot to me, but I will leave to another league to test myself and also grow as a player, and achieve more.