Shlishi: Very good. Let’s say you are right. Al pi halacha, a decedent’s estate passes in accordance with the laws stated in Shulchan Aruch.
Guess what? You can rant and rave all you want, but if Chaim Yankel dies without a will giving away his goods al pi halacha, then IN FACT his estate WILL BE DISTRIBUTED under local laws of intestacy whether you like it or not.
The biggest irony is that the only way he can preserve the default halachos of yerusha is by writing a will, but once he is writing a will halacha allows him to give away his money however he sees fit. So yes, back to square one – unless you live under some kind of autonomous Jewish jurisdiction, the halachos of yerusha do not really have any substantive play in how a person’s estate is distributed after he dies.