Net worth is a pretty useless stat. I do my best to avoid focusing on it (Mint auto-calculates it, so I can't avoid it entirely, but I try).
If you won't be selling your house in retirement to downsize, who cares what it's worth? If you run your car into the ground as you should, what someone would theoretically buy it for today is similarly useless.
Much more useful: compare potential passive income (including 4% or whatever you're comfortable with as a withdrawal rate from retirement savings) with your current spending level. Your FIRE "number" should be based on those things, not an arbitrary number that also includes illiquid assets.
Now, for people who are planning to downsize (or upsize!), or to move from HCOL -> LCOL or vice versa, you also need to make adjustments for that. But again, net worth would be a pretty useless place to start.