Elsewhere in the thread it looks like some ISPs do exactly that! Not sure why you are against the mb/s estimate.

Edit: thanks for the detail re: Mbit in your other answer!

I still think an estimate of Mbit/8 e.g. mb/s would still be a more useful thing for consumers to compare to the download rates they're actually getting.

The first speedtest I ever used was from the ISP and gave results in Mbit -- which confused 12 y.o. me because I was not getting anything close to that when I downloaded files.

If the speedtest said 1 mb/s and then I got 0.8 mb/s downloading from a server, I wouldn't call ISP support, but I think we did call support when the speedtest said we were getting "10 M" but our downloads were closer to 1.1 mb/s.