I once owned a 2013 GTI I purchased new. Wife does lots of business travel and put a ton of company paid miles on it while I would often drive her A4 since I'm close to work.
I did one 7500 oil change but all others were at 5K miles. Had to replace the intake manifold at 80K and clean the intake valves and used vw 504/507 and some ACEA C3 oils after that point on.
Sold the car to brother at 163K He's a pharmacy manager and uses it as his work car not wanting shopping carts, car doors.. to mess up his SUV. He has over 190K on it.
He sticks to the 5K oil changes and has been using Liquid Moly 4200 which is a VW504/507 oil.
I did 5K oil changes thinking 10K OCI's would wear out the timing chain and it's guides quicker.
Issues I had with mine:
Replaced dual mass flywheel and clutch components.
Intake manifold butterflies wouldn't open. Replaced and cleaned intake valves.
Replaced all ignition coils with the latest revision at 100K as a preventative measure.
Oil separator gave out. Look into this one and what to what and listen for. If you continue to drive when this goes out, you can blow the rear main seal
High pressure fuel pump died while my wife was far away from home.
She plugged a code reader in, I gambled it was the HPFP, watched a Youtube video of the tools needed for the job, the dealer had one in stock drove to her and replaced it in 15 minutes.
The car can drive on the in tank fuel pump at a whopping 50MPH max. HPFP on most engines are driven by the camshaft and such vehicles use a second fuel pump in the gas tank BTW.
The whole take away from me is if you put lots of miles on one, 5K OCI's may prevent the expensive hassle of opening up the engine to replace the timing chain and its related components.