I've printed similar objects with a different colored PLA, but I ran out of it and switched to this.
Is it possible that this could be influencing the outcome?
I have tried reducing the printing speed by 50%, but this did not seem to have a significant impact.
[SOLUTION]
The problem was a loose screw. The offending part as well as the new result are pictured below. It's not perfect, which I guess is actually a part of the model this time, but it's good enough for my purposes and way better than what it was before.
I figured this out by twisting the Z-axis thingy manually all the way to the top to see if I could feel any issues. Towards the top, it would start to 'skip', where I would turn and pretty much nothing would happen. I assume this has to do with the lack of lube at the top because my prints rarely go that high. I checked to see if the screws were loose, and sure enough, the top one was. I tightened it up and now my printer is printing like the beast I remember!
Z binding, I think. Your Z axis is binding up either due to issues with that area of your screws or overheating of the motors (less likely). Lubrication can help unless there is an issue of the screws being warped.
Edit: what machine are you using?
Thank you for this information. I am using a Creality Ender 3 V2.
So, this seems counterintuitive, but slightly loosening the part that attaches to the x axis can help as well.
For clarity, you loosen the brass fitting on the x axis that attaches the rod to the x axis.