Asklemmy

Hi, aircraft mechanic here. I don't have a lot of experience with the 787, but here's what I know based on composites, working PAX service, and general airplane BS.
787's are new-ish, but not THAT new. An airplane even a year old can start to show wear and tear depending on the carrier.
787's have composite wings, which flex a LOT. Great for performance, no so great for rigid bits like paint.
Aircraft paint is typically a two-part mixture with an epoxy resin base. It's pretty tough stuff designed to handle temperature changes, UV, abrasion, etc. That being said, paint mixed later in service for repairs might not quite match in color and texture. If the airline buys cheap paint to cut costs, well, it's going to flake off quicker.
Typically, your brushed-on paint done during overnight maintenance isn't going to last as long as the paint sprayed on in a clean, well prepared environment with even application. It's likely you will have to repaint that area.
When I worked PAX, we took extra care to keep the top of the wing painted in good condition and avoid using speed tape to temporarily cover missing paint patches unless absolutely necessary. It's well known this is a high visibility area for customers. From what I recall, the airline would respray entire areas of the aircraft as needed during heavy checks to keep the paint in good condition. Cargo service? Who cares! As long as it meets airworthiness requirements per the manufacturer, send it! Most of the time, the paint is such a poor match it sticks out like a sore thumb. I recall seeing a 747 freighter at one point that looked like it had a green, receding hairline from all the exposed primer it had running down the hump.

So, all things considered, yes, that paint job looks terrible. However, it's not going to affect the performance of the aircraft. Any exposed composite is going to get covered or painted as soon as it's spotted to help protect it and prevent further paint erosion. If anything, all those paint patches might cost the airline a few extra drops (and I do mean drops) of fuel by the end of the flight from parasitic drag.