I was once a the lead guy on a very robust Red Team. Red Teaming kept me sharp. Since I won't be on most engagements anymore, I need a way to stay sharp.
Enter HTB CTF's. These help keep me somewhat up to date. Sure, not all of the boxes require some bleeding edge exploit or zero day, but many do require coding and proper technique.
So to answer the original question. This place is where I post most of the things I do, in the way I do them, to keep my brain up to date and help maintain that Red Team mentality.