Depends on the manufacturer, MSI X570 Tomahawk has good VRMs, onboard sound is still the older ALC1200, which MSI seem to be plugging on all their lower spec X570 boards and B550, not to mention most of the MSI X570 boards have crappy VRMs compared to even the B550 boards, only the MSI X570 Tomahawk and the more expensive MSI boards have decent VRMs, unless you look at their MSI B550 range.
MSI dropped the ball compared to their older B450 range in regards to VRM.
You say 200 quid is expensive,what do you say about the 400 to 900 quid X570 boards?...Most of the top end B550 boards are under £300 and some great ones in £200 to £250 range. X570 is only worth it if you take advantage of the extra PCIe 4 lanes, I know I won't, I only need two ie video card and one M2 SSD (in my case PCIe 3 speed at the moment), so B550 is fine for me especially with ALC1220 onboard sound ,onboard AX Wifi, 2.5Gb LAN etc... (a lot of X570 don't even have those specs), hmm have those specs at a good price or more PCIe 4 lanes and fan?...Think I have something like Asus B550 E Gaming, however I'm holding off for the next gen since in no rush.
End of the day B550 and X570 has to tick all or most of YOUR boxes on what you need and price, I know exactly what I need, so not always clear cut between B550 and X570, since specs between X570 models/brands varies just like on the B550 models from manufacturers.
Always great to have choices
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One of the selling points of the X570 Tomahawk I believe is that they moved the fan so it's not covered by the GPU in most cases.