Why the 74-gun ship became a naval standard

Why did the 74-gun ship become so standard across European navies?

It occupied a particularly useful size-and-cost point for mass construction, while French production and British captures also encouraged standardisation.

The 74 represented a procurement compromise. It carried enough capability to serve in the line while remaining affordable enough to build in large numbers. Larger ships therefore needed a specific justification, and navies did not require as many of them. French construction and repeated British captures also gave the Royal Navy practical reasons to support a common type.