Why was the holy roman emperor a weak title?

Answer 1

There were several reasons why the Holy Roman Emperor's title was rather weak.

One was that the emperor was elected. The emperors were not able to build dynasties that had the power other royal houses had.

Another was that the Holy Roman Empire was made up of a large number of relatively independent states, literally hundreds of them. Some of these were very small, and they included bishoprics, free cities, and communes. Others, such as the Kingdom of Bohemia and large and powerful in their own right. The leaders of these various states were very jealous of the power of their own territories and did not want the empire to gain power at their expense.

The Holy Roman Empire was also mostly German, but not entirely so. The German areas were divided not those speaking High German dialects and those speaking Saxon or Low German dialects. But there were also important areas where people spoke French, Italian, or any of a number of Slavic languages, to name a few. Uniting these people into a cohesive nation was next to impossible.