WI: Archduke Ernest of Austria survives?

IOTL Archduke Ernest of Austria was the second son of emperor Maximilian II, and the brother of emperor Rudolf II. He was also the most likely heir of his brother, but he died in 1595 when he was governor of the Spanish Netherlands.

So, what if he does not die and becomes HRE, king of Hungary, of Bohemia, etc., when his brother Rudolf II dies, instead of his brother Matthias?

From what I can make out about Ernst, he seems to have enjoyed the confidences both of his father, and his uncle/brother-in-law, D. Felipe. Whether or not he was competent, I have no idea. But if we can imagine that he's at least semi-capable, then we might see an interesting time for the Empire.

Other interesting thing is that Philip II of Spain planed to marry his daughter Isabella Clara Eugenia to archduke Ernest and give them the Netherlands, like he did finally with his brother archduke Albert after Ernest's death. If archduke Ernest had lived, and if he had become HRE, he would have united the spanish Netherlands with the austrian branch of the house of Habsburg.