It is important to contextualize what almost all means in this context of a vast and possibly infinite universe. It leaves an incomprehensible number of stars yet to form. It also leaves open a backdoor for a star forming Renaissance if blackhole activity dies down in another 10 billion years.
If we contextualize 95% of all to created stars were created it is still quite a lot dead. Then taking our context which is our observable universe which is only a small part of universe that we care about - we can certainly say it is dead.
Created != dead. The most common stars in the universe have lifetimes many times the observable universe's age. Even if all star formation stopped everywhere right this moment, we'd only be about 1% of the way through the era of stars. In reality, there is a long tail to stellar formation meaning we are actually much less far along.