Maintenance for the week of September 30:
• [COMPLETE] Xbox: NA and EU megaservers for patch maintenance – October 2, 6:00AM EDT (10:00 UTC) - 12:00PM EDT (16:00 UTC)
• [EXTENDED] PlayStation®: NA and EU megaservers for patch maintenance – October 2, 6:00AM EDT (10:00 UTC) - 4:00PM EDT (20:00 UTC)
There is nothing to do with them, they have no purpose. The only reward for doing Achievements is that some give you a title or a Dye Station colour, that's it.
As in WOW, their main use is by the elitists who consider you a 'scrub' if you have less than an arbitrary number, often 10,000 but sometimes as high as 15,000 or even more.