I've been there.. but as other players have pointed out, it's not that there was nothing left to do, I was just burned out and not wanting to do what was left to do. Here's a quick rundown of stuff:
Triple Elite
King
Admiral
All 20 engineers unlocked to grade 5
All system permits
Buy all of the ships you like
Truly learn how outfitting works. I've seen tons of people just throw stuff together, Understand DPS, understand incoming and outgoing resistances, understand shields and hull, understand thrusters.
Now go engineer all of your ships. Learn what true god-rolls are. Learn the max you can get on every module and shoot for that.
Build the highest DPS ship you can come up with. Now re-do it so it doesn't cook itself.
Build a racing ship (Courier, iEagle, ViperIII, etc) that exceeds 850m/s
Build an Anaconda with a jump range that exceeds 60ly
Alternatively, build an Anaconda with the most extreme jump range you can come up with, then stack an FSD boost and a neutron star and set a long jump record.
Build and then learn to effectively fight in a Railwinder
Train Harmless NPC crew up to Elite
Do PowerPlay if for no other reason than to collect modules
Visit nebulae
Visit black holes
Visit mitterand hollow
Visit Betelgeuse
Visit all of the generation ships
Visit Dav's Hope, Orion's Folley, Stranded Snake, Lewis Lost, and all the others.
Visit the Formadine Rift including the Zurara.
Visit some Asteroid bases and some Mega Ships
Here's a good thread for POIs:
https://forums.frontier.co.uk/showt...s-CQC-structures-and-other-new-in-game-assets
Land on Achenar 3. Do it again in a big ship.
Visit the Guardians sites, do the Ram-Tah mission.
Visit the Thargoid sites, get hyperdicted
Go see all of the different planetary things, like brain trees, space pumpkins, geysers, lava sprouts, barnacles, and whatever else is out there.
Join the Fuel Rats or other in-game groups.
Go to Colonia
Go to Sag-A
Go to Beagle Point
Achieve Top 10 (not top 10%) in a CG or two.
If it's cash you want, engineer a combat ship and stack massacre missions. Even three at a time you can make bank doing them as long as you have a really good ship. Stop when you reach however many billions make you happy. Or don't stop at all.