There's a solution to all this... Stop seeing racing as an 'arms race' and don't take the results too seriously... the only thing you should really take seriously is to try and have fun
I'll explain my perspective on this... I started racing in 2012. As I became more experienced in racing and I developed my buggy further, results improved and where initially I rejoiced my new personal best results, being in the top 3 at club races and A-finals in Nationals became the norm and a personal expectation a couple of years ago. The consequences of that are awful, as not meeting an expectations results in disappointment.
When you don't achieve the results you expect, it becomes very easy to talk yourself into the idea that you need to prepare more and better to practice your hobby and have fun, and that better equipment and tires will help you achieve those goals. However better preparation or gear does not guarantee fun, in fact it makes for only bigger disappointment when things don't work out as you expected.
At some point a few years ago, further preparation did not improve my results and I was not having the fun I wanted. I had a good think and I decided to not do any preparations for the next race and not drive in in my usual class (2WD modified) either. Instead, I got my box stock Tamiya DT03 off the shelf, charged the battery and nothing else. I had a blast that day, it was the nicest day racing I had in over a year! Since then, I've gone back mostly to club racing, I prepare a lot less and the hobby has been all the more fun for it.
So if you ask me, the best thing you can do is to ignore the level of preparation you see around you, don't let yourself get involved in an arms race of more tires, the newest cars and go to the track without expectations with regard to results
Worn tires, a slower motor and last year's car will not stop you from having fun if you won't let it.