The only speeds that are guaranteed are the speeds printed in the specifications on the box. Strix 2080 Ti cards already run well above Nvidia's baseline speeds. Other brands with improved cooling have similarly offered products. Any speeds ABOVE what the advertised specifications are for the GPU are not guaranteed and are simply luck of the draw. Those of us in this hobby for some time know this. It's not a conspiracy.
Yes, buying a good brand GPU with quality components and cooling may increase your odds of a higher clocking card. That's why these products sell. At a minimum, you will get the speeds advertised (or be eligible for an RMA). No offense to the OP here, but whether you get another Strix or another brand, it will still be a crap shoot.
If you want improve your chances of winning the silicon lottery, buy your hardware from large retailers instead of going to boutique shops. This will reduce the possibility of having stock being "gone through" and having the best items already cherry picked out. Most GPUs come sealed though....so you see a lot less chip binning with GPUs versus CPUs from the boutiques.
Funny side note, my current 9900k that does 5.2Ghz at 1.35v was bought retail from Newegg and completely outperforms the chip I had acquired from Silicon Lottery (which I subsequent sold). That's the lottery my friend.