There's a wide range of Meguiar's products available. It all depends on the surrounding conditions and your detailing habits. Some people polish and wax their car every year, some do it monthly.
My car isn't much driven so I really don't need to put in much effort, but yeah I wash it every week and wax it every 6 washes, but waxing isn't required to be done this often normally, this is only because I like spending time on the car.
You can use Gold Class and NXT 2.0 and notice how the results will be SO much better than your Royal Shield, you'll notice more depth and gloss in your paint and yes it will last long.
Giving your car regular attention is better than getting a 2-year RS and risking your car's quality paint job.
These are swirl marks which can easily be removed without Royal Shield.