A motherboard rarely gets the attention of a CPU or graphics card, but it decides how everything connects and how easy future upgrades will be. It is where your processor, memory, storage, graphics card and peripherals all come together.
Choose the CPU first, then look for the ports and expansion options you will genuinely use. Extra M.2 slots, Wi-Fi, more USB ports or better room for upgrades can be more valuable than features you will never touch.