My experience is that you need to play against people who will challenge you, but within an appropriate level of attainment. I am a keeper, so I will speak of keeper skills.
One important skill to learn early is to get off the line and cut off the angles. If you stay on the line when you are just learning, the net is too big and you have no chance to make saves.
Thus, you never learn to make saves because you have no real feedback on what you do. You always lose.
Now if you come out a bit, you start making some saves, and you get better at it. This would lead you to a place where you make nearly all the saves, and you would stop learning, unless your opponents are good enough to use passing and make you keep track of multiple strikers at once.
But if they are so good (or your defenders are so bad) that they are always swarming the net in threes and fours, you would get stick on the line and never learn anything.
So, the best way to learn is for your opponents to be better than you, but not so much better that they discourage good play on your part. And as you get better, they must get better as well, so that you must continue to get better.
This is very common with foos ball. There are local maximums where a player can get stuck. If you're playing opponents as good or a little better it pays to practice your foosball skills like passing and high accuracy shots. However if you're playing opponents far stronger then the best strategy is lower percentage Hail Mary's so it trains less important skills.
My experience is that you need to play against people who will challenge you, but within an appropriate level of attainment. I am a keeper, so I will speak of keeper skills.
One important skill to learn early is to get off the line and cut off the angles. If you stay on the line when you are just learning, the net is too big and you have no chance to make saves.
Thus, you never learn to make saves because you have no real feedback on what you do. You always lose.
Now if you come out a bit, you start making some saves, and you get better at it. This would lead you to a place where you make nearly all the saves, and you would stop learning, unless your opponents are good enough to use passing and make you keep track of multiple strikers at once.
But if they are so good (or your defenders are so bad) that they are always swarming the net in threes and fours, you would get stick on the line and never learn anything.
So, the best way to learn is for your opponents to be better than you, but not so much better that they discourage good play on your part. And as you get better, they must get better as well, so that you must continue to get better.