Write down exactly what's needed in your build. How many fans, how many headers, how much storage and their exact requirements. Usb internal headers, all that stuff. Pick a motherboard. Doesn't matter which, B550 or X570. Ignore the hype on the first page, skip right to the detailed list. Compare that to what you wrote. Does it cover or even exceed your wants/needs, is it reliable and worth the outlay of cash. If not, is it a chipset limitation or brand limitation. Find out by choosing another board from another brand. Make the comparisons.
By the time you are done weeding out the useless fluff, you'll end up with 3 or 4 mobo's that fit. Then look at any extras, gimmicks etc like faster Lan or better audio or better software etc. You'll find your board in the end, based on what you wanted and what's of value to you, not what someone else says is good or ok. Might just include time spent on figuring out the differences between B550 and X570 and whether that'll be of benefit and value for the price difference.
It's quite a bit of research, but worth it in the end.