[jsmith45]

The current global rule limit is 300k rules per profile. This is shared between all extensions, which is shared amongst all extensions. This limit comes after the 30k per extension minimum, so if your extension uses 40k rules only 10k count against the global limit.

So if we assume rules are 1-to-1 (and in fact fewer rules should be present in declarativeNetRequest because certain rules like element hiding do not factor into declarativeNetRequest, and would be handled directly by the extension), you could fit ~5 adblocking extensions the size of your basic ublock install, and most of a 6th.

Now there are some advanced capabilities of some adblockers that have no equivalent available, but for common multi-plugin rulesets like EasyList, declaritiveNetRequest will support pretty much everything contained therein, (except cosmetic rules, which the plugin must apply separately, since they are not blocking requests, but modifying the page, which is quite different).