I remember a long time ago was trading in a 3 series in about a week, I knew tyres had got down pretty low but still legal and obviously didn’t want to waste money replacing them when it wasn’t going to be my car soon.
Anyway normal rain and didn’t have much issue but got caught out in an absolutely massive dump of rain from the heavens on a motorway. I had to slow down to about 50, maybe a bit under even as anything above it was constantly losing traction. First time it did it at 70 was a bit hair raising.
Long story short, the guy is onto something
99.9% of the time you’ll be fine but if you get a super heavy down pour with low tread, really slow down.