Your motherboard limits what CPU you can use by the CPU slot.
Yours is an LGA1151 which means that these are the CPUs available to you:
Asus STRIX Z270F Gaming CPUs
You have 2x PCIe 3.0 slots available for GPU, and although the 3080 uses PCIe 4.0 this wouldn’t be your main bottleneck.
Your CPU will limit the actual performance of a 3080 but that’s mainly in MSFS from what I understand. There are plenty of games that will benefit greatly from the 3080 and not be as CPU bound as MSFS.
I’ve got the Intel i9-9900k with a similar chipset (Z390) and I will be getting the 3080 when it’s available. BUT the new Big NAVI cards from AMD will probably be available before I can get a hold of the 3080, which might make me change my mind…