It's great that this has been your experience. I have had plenty of rides with nothing but great interactions with other people using the roads, too.
Looking at my stats I have reported far fewer drivers for dangerous driving than usual, only one in April, one in May and one from this Tuesday.
Twitter can make it seem like you will encounter a homicidal driver every time you get out on a bike, when you get to hear about so many more nasty incidents which aren't reported anywhere else.
Blimey! How many do you normally report?
When "lockdown" first started I was impressed by how few cars there were about, though even then subjectively some were enjoying the empty roads by driving fast, but I had no instances of close passing, abuse, flying beer cans or anything.
Even as people "gave themselves permission" to start driving more for less essential reasons and more vehicles came out it was noticeable that they gave me plenty of room. Once the official easing of restrictions started it was quite noticeable how many more cars were about but still not up to pre COVID numbers.
Yet so far they seem to be behaving themselves space wise, even to the extent that if I pull towards the centre line to give pedestrians "social distancing", cars behind will either wait or go right across into the other lane to pass. No doubt I am inviting some kind of retribution by even mentioning it for next time I am out but there it is.
I am not saying that all the drivers I have come across are raving philanthropists but certainly at the times that they have passed me (and almost everything does) they have been in a frame of mind to give a solitary cyclist some consideration. I am not above giving a little wobble when I hear something coming up behind but that does not explain the greater than usual numbers of overtaking vehicles that pass in the other lane.
(sports bikes / sporty cars) - since when did a 20 limit become a 40 limit or a 40 become a 60/70/80 
(Covid-19 perhaps affects basic numeracy as well as smell and taste?)
