So I started rank tracking some prospective clients I know are not doing SEO a few weeks ago. I also have some existing clients in the same exact industry but in different cities. It's been really helpful watching the rankings of site that are not undergoing SEO and comparing them to my client's sites. When I was only watching my clients I would flip out at every big rankings movement, thinking it's my PBN or something. But by having a baseline to compare to (sites not undergoing SEO) it's removed all anxiety I have about rankings. These sites are moving just as much, and sometimes in total opposite directions despite not having any links built to either of them. My point here is the SERP's are crazy right now, but if you can find some sites that are on page 7 or 8 (for the KW's you're targeting) that do not have links built to them, tracking them can give you some better insight into whether or not the problem is with your site or if it's natural movement cause of the algo.