Why not both?

Low birth rates —> neoliberals need workers so they increase immigration —> influx of religious zealotry fuels cultural friction.

Yeah people like to ignore Albanians, and also forget that Turks could be argued to be culturally closer to Greeks than they are to Arabs. Albanians are also not really religiously Muslim, but rather culturally. Not so much because of enforced atheism under communist rule but because the whole experience left people with a sour taste for taking religious ideologies (too) seriously. There's some fun polls for Muslim countries which I can't find right now asking things such as "is there a god", "does heaven exist" etc. and it figures that Albania, alongside with Iran of all places, is one of the countries where people who call themselves Muslim aren't doctrinally Muslim because they don't accept the full set of core tenets but some eclectic mish-mash. To have a comparison: That's like Christians who believe in reincarnation.

The main issue I think is that there's no established European Islam: Albanians aside, which generally aren't even noticeable among the immigrant population in other European nations, Islam in Europe is dominated by non-European interpretations. Other states are sending Imams here which often have no idea about life in the countries they're preaching in, and that's before we get to Salafis, Iranian operatives, and like ilk, who are causing havoc deliberately. Suppose you're Indonesian and live in Hamburg and want to go to the Mosque, where do you go? To Turks? Arabs? Persians? Neither speak your language, neither are culturally or theologically anywhere close to what you're used to. A German mosque? You might not be fluent in the language (yet), it might not be anywhere close to what you're used to, but you're learning the language anyway and trying to integrate so yeah that's an obvious choice. The community is headed by a learned Imam who definitely knows better Arabic than you so it can't be all heresy. The alternative is some Salafist noticing you being lost and trying to radicalise you.

Germany had quite a long discussion about the whole topic, more than a decade at least, and by now there's the first Imams educated in Germany. I kinda doubt such a thing is easy or even possible in, say, France, which is way too secular for politics to even touch religion with a ten-foot pole (the Muslim communities wanting to build that Imam training centre got state aid to establish it), or on the other end of the spectrum the Nordic countries, which have a single instead of a multitude of state churches.

Also the Serbs were good in committing genocide in Bosnia to wipe out the Muslims from Europe!!!!!! We should have kept supporting them!!!!, like some politicians back then, alleged and some people now try to revise the history of the genocide...

Islamophobia is genocidal like Antisemitism and other bigoted ideologies.

It is crazy how now a lot of the same sentiments are nurtured and normalized now against Muslims, that grew into the Holocaust against Jews 80 years ago.

Yeah, fuck the religion of 2 billion people in the world... Also look at our great secularism, that is forbidding women what to wear in places like France and Germany and killing hundreds of thousands of civilians who have the wrong religion or skin colour in the past decades and millions in the past century. What a great civilatory achievement!