A moral society is not "a society with arranged marriages." It's a society without laws that favor women, which is most laws if not all of them.
If such a society were to exist, women would be economically forced to "sexually desire" (have sex with) much uglier men, since the government wouldn't be bailing foids out with incels' money as is happening now. Foids would need a man that could stick around and provide.
Women are biologically hardwired not just to want children but to be able to provide for their children. Many Chads can't provide for foids' children, but the government right now is stepping in and providing for foids in Chad's absence, which gives foids the ability to recklessly fuck Chads and gives Chads the ability to pump and dump foids without having to be a provider for the many babies he creates.
This, combined with other insane foid-favoring laws such as taxpayer-funded abortions, public healthcare, etc. is the root cause of inceldom.
Whether any particular incel would end up with a partner in such a society is far from certain. If, for instance, you're 5 feet tall, 300 lbs. and disease-ridden, then you're still unlikely to be having any sex regardless. But generally speaking, incels' chances would improve dramatically if women no longer had the power of the government behind them.