Separate root fs makes it easier for timeshift.

How? I use timeshift. I don’t see what you mean.

Also makes it easy to install another distro and pick up where you left off with the old home.

Sure, but how often do you distrohop? Not worth the trouble to have to potentielly mess with partitions during everyday use.

When I do reinstall, I’ve just copied my home folder over to a secondary drive, then back again.

If you alocate 50-60 GB for system it should be ok.

That’s the entire boot drive on some of my machines. Not to mention that I have gone well beyond that for root on some systems. You just can’t know the numbers in advance, and when you want to just use a system for something, it’s really annoying to have extra steps.

Making home a separate partition just makes it really hard to use the full capacity of the drive, should you need to. Which people do need to do sometimes, even if only temporarily.

Doing this might make sense if you have terabytes of storage to throw around, enough to never fill any of your volumes. It has benefits, but not enough to make it good advice across the board, which is why I question it.