You can tell that to the people in Houston who lost their home overnight. Home ownership is not risk free. ;)

I am not familiar with the entirety of the US territory. If you look at properties outside of the major cities, they should be relatively stable, renters have no jobs to sustain ever increasing rent. In the far country side, properties should be deflating because de industrialization.

Agreed that it is great for a diversified portfolio. Especially the primary home, it's self sustaining because you'd have to pay rent anyway. A second home is safe, it can host your child now or yourself after retirement, then it's lower returns.

There are a lot of index funds with various risk profiles. There is no general strategy. It depends on your personal situation, how much there is, where your live, and you family.

Now, that might sound stupid. If you own your home and have some savings, you can basically retire. There aren't much expenses outside of the rent.