no, all that suspend blockers do is to tell the system that while suspend is blocked, don't run your normal heuristics.
When suspend is not blocked, the system can run the heuristics to decide if it should suspend or not.
suspend blockers may allow yo to set the system heuristics to be more aggressive, but if you have any apps on the system that do not invoke suspend blockers, you run the risk of suspending too aggressively when those apps are running.
And if an app claims that you should not suspend (by setting a suspend block), then the system will never go to sleep.
this is very similar to cooperative multitasking, when all apps are well written it can work _very_ well (and can be far more efficient than premptive multitasking), but it only takes one badly written app to cripple the system.
There's a reason that there are basically no commonly used cooperative multitasking systems, in the real world they just aren't reliable enough. The only place you can really use them is in embedded situations where you control everything that's running on the system. That no longer includes phones as people can download apps to run on them.