As the title implied, it would be wonderful if we could have a team with only one mission.
Take the low resolution wallpaper in some beatmap that managed to be approved somehow and find them in their original quality to replace them. Of course, this project presents some flaws like the fact that the dev team is probably busy with other business, but I kept that in mind and thought of a system that could involve the community while limiting the risk of diversion of use (Not keeping the same image). First of all making it a paying privilege on top of requiring the supporter status would be a good way to keep only serious people in this team. Then to make sure we only have well-meaning people fulfilling this duty, let's do a little simulation.

Let's say that I am part of this team, I found a picture of a very bad resolution on a beatmap and after a little research on my best friend google I find a much better quality of the SAME picture. The idea would be that I could place a request to replace it and for it to take effect, I would need X amount of vote from the other members of the team or 1 from a dev to approve this request.

***

EDIT: Simply presenting here a concrete example with an existing beatmap to better demonstrate the idea.

So the beatmap that will interest us in this example is this one: https://osu.ppy.sh/b/707461
This is the file of the background in it: http://www.mediafire.com/view/oeam4l6qlbm1rms/BG.png
And after just a quick search, I was able to find the exact same picture but in this quality instead: http://www.mediafire.com/view/odg3e558jqp8pmu/BG%20UHD.png
Also here is 2 in game screenshot to better visualize the result:
Actual background -> http://www.mediafire.com/view/zsb35g62bc60ysc/screenshot001.png
Maxres Squad in action -> http://www.mediafire.com/view/ob0a6t41k4ajqd4/screenshot002.png

***

In conclusion, I am convinced that such an addition will be well received by the community and really appreciated. And personally I would pay at least 20$ a month to join the crew. I hope you will be convinced by my arguments and I would be happy to hear your opinion on the subject whether it is positive or negative.

-Source picture: https://i.pximg.net/img-original/img/2016/11/24/00/02/08/60082303_p0.png
-Artist PixivID: 凪白みと

Looks like a good idea, but it's not needed nor necessary. If it happens, this will only apply to beatmaps that are either ranked/approved and not only require an approval from the devs or the QATs/GMTs, but also the beatmap creators themselves. Changing these backgrounds without their consent is definitely a bad idea.

Let's say:
1. A member of this team suggests a background.
2. Other members will discuss and upvote/downvote it.
3. If X votes are achieved, the creator can confirm the update.
4. The osu! team approves the update.

I think you misunderstood the idea here. The point is not to suggest a new background. The main goal is to replace any low resolution images with the same picture but in a better resolution. Thence all my previous precautions.

Technically, that's the same. You're suggesting a new background with a higher resolution.

Sorry if I took a little time to answer you and thank you so much for the attention you give me. I really apologize if my words aren't good enough to explain you my thought. Since I really care about this project I went ahead and found you a real example with an existing beatmap. I also took you some in game screenshot to better visualise the general idea.

So the beatmap that I choose for this example is the following: https://osu.ppy.sh/b/707461

The actual background in it that as a really bad resolution is this one: http://www.mediafire.com/view/oeam4l6qlbm1rms/BG.png

After just a quick search, I was able to find the exact same picture but in this quality: http://www.mediafire.com/view/odg3e558jqp8pmu/BG%20UHD.png

And before you say it's not a big difference here is 2 in game screenshot to better visualize the situation:
Actual background -> http://www.mediafire.com/view/zsb35g62bc60ysc/screenshot001.png
Maxres Squad in action -> http://www.mediafire.com/view/ob0a6t41k4ajqd4/screenshot002.png

Note that this is not one of the worst case I've seen but I hope you get the point now.
I also took the time to edit my post so it would be clearer for everyone from now on.

creative idea indeed but unesscessary tbh

I think that everyone can appreciate a good wallpaper in ultra HD, so it doesn't seem completely unnecessary to me, but I can't unseen the fact that if you exclude me that's 2 in 2 who finds it superficial so I'm starting to be skeptical myself. Long live to the 90% compressed lowres JPEG file FTW I guess...

Joke aside, I'll come back tomorrow to see if there's any change.
In any case, thanks for the feedback. If it achieves to grab your attention, that's a good start for me. ^^