It's true, you can cut off the data stream. I have done so, at times, myself. At this point, though, I have it on (with some device exceptions where I do anything that might be sensitive, or I might want to avoid someone accidentally finding out [e.g. gift purchases]). My reasoning is that I am likely being tracked no matter whether it's on or not. At bare minimum, even with stringent cookie policies and software removing "tracers" on a regular basis, my cellphone carrier, or isp, can track what I'm doing, unless I have a VPN on. While I don't mind having a VPN on, when I don't have it on, it makes the most sense to me to be able to view just what I've been doing. I like having that log, because I then have an idea of what other companies know about me. It sucks that I'm put in the situation where handing over my data to someone who does the responsible thing and reports it to me is a sensible choice in my eyes.

So I'm using stock LG G3 Android Marshmallow (completely stock manufacturer ROM). I have Google settings kinda locked down as much as possible and I've been carefully managing app permissions since I upgraded from Android 5.

My google activity shows only google maps searches from the device and some google website searches from desktop (probably from when I happened to be logged into GMail and made a search query via google.com).

I use Gmail on Android, Signal for SMS (no-one I know uses Signal) and Firefox with self-destructing cookies and uBlock origin (I use a similar setup on desktop too - to prevent persistent logins) I can't see any other activity being logged. That's not to say that it isn't flowing through Google's pipes somewhere or other.

My point is that I'm only conducting basic privacy measures but (as in, not having to root or reflash my phone) - and not having most of my activity recorded in this dashboard.

I'm a bit surprised, I was using the stock Android for Nexus and in my case the results were logged. Just as other people are reporting: every single application usage, call or what-have-you. I also had turned off everything I could find in Settings -> Google Account.

Do you maybe have multiple Gmail accounts? My first time visiting the link above, it only had 3 YouTube video views from this week. That was before I changed the selector from my work account to my personal gmail account. Then it correctly showed a very detailed log, like that I had opened Spotify 2 minutes ago.

What is the benefit of running it this way? There is additional cost of burden with doing this and I am genuinely curious.

Does the cost out weigh the perceived benefits?

I think they know much more than they are showing in that dashboard. Simply staying a few steps ahead and not giving them the option to even link to your account is worth for me.

To give an example on desktop, even using separate Firefox profiles for Google and non-google activity, it is embarrassingly easy to see that the activity comes from the same person. Just cross-check the bonanza of information like screen size, plugins, fonts etc. I would be surprised if they didn't do it. I prefer to not run the risk. So I go to even greater lengths than I mentioned above, however it was getting long.

To come back to your point, it's inconvenient only in the beginning to document yourself and to set it up. Whether it is rooting the device, or setting up your own e-mail server. In the end it is about the freedom of computing whatever you want on the device that you own.

EDIT: If I may add, it's not like I'm going full Stallman. Everything is a compromise, it would be nice if we weren't forced to go to these lengths, or to compromise at all.

So the perceived benefit to limiting them is to stay ahead of them in what they know about you?

Yes. Through technical guarantees, I like to think that the benefit is not merely "perceived". And it applies to other actors as well, not only Google.

You could also just turn the stuff off.