Based on my admittedly incomplete readings of the Bible and the Quran, they're pretty close to equivalent. The Quran, if anything, leans harder into telling people not to be a dick.
The practitioners are roughly equivalent, too. You can find peace lovers and warmongers in both. I think the ratios are a bit different, but that's not down to the content of the religion but the context of the believers. Islam is newer, it's dominant largely in areas that are geographically and economically disadvantaged.
It seems to me that people who are doing well, have stable lives, tend to be more peaceful in general. It also seems to me that the older a religion, the more peaceful because the practitioners have had enough time to chill out.
I don't agree with that statement, because both on paper and in practice, Christianity is no better or worse than Islam. The only reason Christians aren't slaughtering homosexuals and transgender people the same way is because they've been leashed by secularism. It's not that they haven't or don't want to again. It's that they know they can't get away with it -- yet.
Look at organizations like Seven Mountains and other Dominionist groups promoting Christian Nationalism. It's not a coincidence that Kevin Swanson regularly sees Republican office holders at his "Kill the Gays" rallies. They don't hate Islamic theocracies because of the theocracy part. It's that they're jealous of their religious power and want to surpass it.