It's funny how Microsoft conducted the "tests" on Chrome [1] & Firefox [2] and discreetly leave out Safari. Safari is by far a winner when it comes to efficiency. So hats off to MS for their "informative" & "thorough" test(s).
[1] has been known for draining battery, so no surprises there.
[2] which for a couple of releases has become even more unusable. On my MBP (2014, i5, 8GB), takes over 4+ seconds for the bar to activate. Hopefully with the introduction of E10S [3], next releases will be much more perfomant.
[3] https://wiki.mozilla.org/E10s
EDIT: I did not know Safari is no more on Windows. So in that case Edge is the winner for Windows.