Only 31.5% of homicides are committed by non-Hispanic whites [1], while they were 57.8% of the population. That brings the white homicide rate to 3.14, which, if you squint, is pretty close to the Canadian 1.98. The common misclassification of non-white offenders as white (but almost never the reverse) [3] probably explains some of the remaining disparity.

So in that respect, whites in the US are not so different from whites elsewhere.

[1] https://ucr.fbi.gov/crime-in-the-u.s/2019/crime-in-the-u.s.-... (I think due to incomplete reporting, and due to including only cases where some information about the offender is known, the absolute numbers do not reflect the number of homicides in the entire US, but it is still useful for relative comparisons)

[2] https://en.wikipedia.org/wiki/Demographics_of_the_United_Sta... (using 2020 numbers, which are close enough for the 2019 FBI stats, which are the most recent I know of)

[3] https://threadreaderapp.com/thread/1700341490206310416