A recent commit in the Android Open Source Project Gerrit revealed that Google is working on adding hardware support for multi-SIM capabilities. One of the comments from a Googler suggests that the upcoming Pixel 4 will be packing support for eSIM and a physical SIM with dual standby.
https://www.notebookcheck.net/Google-Pixel-4-could-support-both-physical-SIM-and-eSIM.406221.0.html
I think if they want it to sell well there need to be two implementations two this smartphone.
1) One should be able to save contacts to device/smartphone and not be forced to save all contacts to Gmail with no option to choose from like other smartphones.
2) If dual sim is to be useful it needs to be able to allow end users to be able to install apps on both sim cars otherwise useless for many that travel abroad. In Asia the Chinese smartphones sell well because one can install two WeChat apps on their smartphones that have dual sim capabilities. Their personal and business can then be separated on one Smartphone instead of needing to carry two around.
I guess that for the second part you can simply have two separate Android user accounts. What do you think?