Why do you ask? Real question, not snarky -- I think for many people who are good with money, the detailed tracking and calculating and all that comes naturally -- the attention to detail and the frugality are both just different parts of the same personality type. I am not a detail person, so I just don't get the same innate joy over that kind of focus. I'm going to assume you are more like me, because, duh, if you loved-loved-loved that kind of thing, you'd already be doing it, right? So the real question is whether it would be worth it to you. From that perspective, I see two related benefits:
1. Control. Many times, the journey to FI begins when you feel out of control -- you feel like there are a million moving parts, and somehow you always end up tight/short every month, and you just don't know why. Paying attention and writing everything down tells you what is coming and going and identifies the gazillion little leaks, so you can then make changes -- it begins to put you in control of your finances instead of the other way around. Of course, that's largely focused on tracking, not net worth. Which brings me to . . .
2. Progress! When you start the journey, it can feel like very slow progress, because most of the early days involve paying down debt, whether it's CC debt, a mortgage, student loans, a car loan, etc. So you may be looking at your investments, and maybe you only put in $1K this whole year -- but maybe over that same year you paid down $10K of debt. That's a big win, even though it doesn't show in your bank account. Tracking your net worth helps you see that you are making progress in a way that focusing only on the amounts in your savings/investments does not.
So the tl;dr is that tracking provides the most practical benefits, but net worth can provide an emotional boost when it feels like you aren't making progress. Of course, it can also provide a false sense of security if all of your gains are attributable to a raging market and not your own efforts, so take that with a grain of salt, too. :-)