The Lubavitcher rebbe counseled many rabbis and other community leaders not to make aliyah, because otherwise they would no longer be able to have positive influences on the Jews they left behind in chutz la’aretz.
Aside from that, most of us don’t really have any excuse aside from convenience. If most of us were to uproot ourselves and give ourselves a few years to try to live in Israel, learning the language and finding an income and so on, most of us would find we can make it. It would just mean a few years of uncertainty and adjustment difficulties. In some places most are Anglos and you can get by with English much of the time.
There are extremes in Israel but there are also those in between. There are certainly American-style moderate charedim. There are even neighborhoods full of them. The dati leumi are increasingly frum (and less rationalist than MO, due to R’ Kook’s mysticism). Most “chilonim” are more religious (and far more likely to be halachically Jewish) the Reform or Conservative Jews here (the vast majority of chilonim fast on Yom Kippur.) There’s a tiny minority of radical leftist self-haters but most of the non-Orthodox are relatively traditional and respectful toward religion.
Terrorism is a problem, but the murder rate is still much higher in America. And I’d trust the IDF to keep me safe more than the American military any day (here more likely to make us less safe by engaging in unnecessary wars).
The main thing is assimilation. If your kids c”v’s go OTD in Israel they will most likely still marry other Jews and have Jewish grandchildren. It is only a matter of time before Israeli is majority Orthodox, which will eventually inspire those grandchildren to make teshuvah. In America OTD kids marry non-Jews, have non-Jewish grandchildren, and are lost to the Jewish people forever.
How many more millions of us need to assimilate before we get the message and move to the Jewish state?