Does everyone use a rank tracker?

Hi, pplz. Yes, it’s been a while.
I am (finally) getting to re-doing a lot of my SEO work.
I’m relearning SER, because I know I wasn’t using the software to its highest potential, and starting with the manual seems a good idea.
But I’m only on page two or whatever, and there’s discussion of tracking ranking of keywords with (I have never used this service.)
Anyone have any comments or feedback? Anyone think it’s a vital service?
As it’s mentioned so early in the manual, I am thinking this is important and I should go for it. And so, I am signing up and I’ll see how it affects everything.
I used to manually check KW ranking, or use SEMrush. Is there anyone who feels working without a rank checker in SER would be like working blindly or really awkwardly? Any thoughts would be much appreciated. :)