It's not exactly a new thing. People we would describe in the modern day as "religious extremists" or outright authoritarians have been using he name of Christianity in this way for... Well, since Christianity was invented.

Same for Islam and Judaism, though the last one has the roles reversed.

The problem you're trying to identify here is how the public and historic narrative almost completely ignores any positive aspects of these religions and focuses exclusively on the actions of terrible people using religion as cover and justification for terrible acts.

In large part it's relative to location and culture. In the US, if you ask any random person their opinion of Islam, it will be overwhelmingly negative. Vice versa in Islamic societies about Christianity.

There's also a lot to be said of the last era of colonialism wreaking unthinkable damage and actual literal genocides under the name of Christianity, and the damage that Christian "missionaries" still do in the modern day. In recent history, a lot of very, very bad things have been done very loudly in the name of Christianity. Under that banner, Europeans destabilized and destroyed huge swaths of the world. The consequences of which will still be around for generations yet to come. That kind of thing leaks into public and historic sentiment, no matter what. Turns out that the public doesn't really like genocides.

Before I get replies, yes, other people have used other religions to also do terrible conquest and genocide. European Christian colonialism is just the largest and most recent example relevant to Western common knowledge. You should study foreign religions and form your own opinion, it's quite enlightening.

On the other hand, the narrative of the modern era is completely and totally dominated by sensationalism and all the problems that capitalist media bring. Stories about Christian groups donating money don't sell news subscriptions or ad time. Ragebait does, and many religious groups of all flavors are happy to oblige.