This is correct. To expand: things like installed extensions, window size (as well as monitor size), bandwidth and general user speed, adblockers themselves and their individual block lists, and browser are all adding to your trackability profile.

I believe you can get specific information about user's operating system (either through legitimate, direct checks or by exploiting features and using process of elimination such as X version of Chrome is only available on Mac) and of course hardware IDs.

Your IP is obviously out there as an obvious profile that can build a general picture of you in a very similar way to phone numbers. If you use a VPN, the IPs bought by that can also be profiled to narrow you down. If you’ve seen a denial message telling you to not use a VPN, this can be what’s happening.

There are also just official exploit-tier-like features constantly being added. For example, Chrome is adding the ability to see if you're idling on a page.

I've noticed some major internet sites compiling this type of information for use in, for example, permabans. Trolls have otherwise been able to use a VPN or just create a new account. This is a large driver of finding new tracking methods outside of just personalized ads.

I think a lot of this is in its relatively infant stages. I suspect it'll be 5 to 10 years before people become aware and some newsworthy incident of major abuse occurs.