Muslims, especially in France, are more likely to be on the end of a holocaust than Jews. They're the ones the far right is rallying against across Europe.
Just to be clear, I agree with you this statement 100%.
I'm just observing the numbers. Nearly 10,000 French Jews are moving to Israel every year. Even if they're completely deluded in thinking that France is bad for them, that's a big number. The flow may slow down, but it's not going to reverse overnight.
By and large, the Jews who are leaving France are religious and Zionist. Their influence on French religious life is disproportionate to their numbers. Even if France is, today, a totally great place to be religiously Jewish, a decade-long exodus of its most committed members won't be good for the strength and vibrancy of the religious community there. In other words, the France they're leaving today is not necessarily the France they would be able to return to in a decade.
It would take a lot to grow this relatively modest rate of Jewish emigration from France to Israel and not much to reverse it. Unlike the Russian example, there isn't much of a pull to move go Israel for a higher quality of life. For the same reason, emigration from the American Jewish community is pretty low.
The situation in the US (and the rest of the Anglosphere) is totally different than in France. The US, and to a slightly lesser degree the rest of the Anglosphere, offers Jews the highest quality of life of anywhere in the world, including Israel. Jews from the US have zero reason to leave (which is why none of them do), and Jews from other English-speaking countries are just as likely to move to the US as to Israel.
The situation in France is not remotely the same. French synagogues and Jewish schools have security guards. I've never once seen a synagogue in the US that restricts admittance, because literally no one here is scared of being attacked for being Jewish. Do French Jews have any legitimate reason to be scared? Maybe, maybe not; certainly, they have far less to fear than Muslims. Regardless, French Jews are scared, whether or not they have a reason to be. And French Jews have another country to go to, one that will take them in and keep them relatively safe, which is not true for many of the Muslims in France.
French Jews have just as much of a language barrier in the US as in Israel, if not moreso (since there are communities in Israel where everyone speaks French). They have a much more difficult time becoming US citizens than Israeli citizens. And since most French Jews are Sephardic, they're less likely to be treated as "white" in the US, or to feel welcomed in the Ashkenazi-centric Jewish communities here.
And once they have kids in Israel -- kids who grow up speaking mostly Hebrew -- it becomes that much harder to leave.
Again, I'm not saying that there won't be any French Jews in 5 years. At the current rate, it would take 50 years until every French Jew had left. And plenty of Jews in France will never leave, whether because they're not religious, or not Zionist, or just because they're happy in France. I just think you're overestimating the willingness of the already-departed French Jews to move back from Israel, and that you're underestimating the impact that their departure, even temporary, will have on Jewish religious life in France.