Allows farmers to raise water from creeks upward, to fields, where it can be used for irrigation without a power source. In the early part of the Industrial Revolution, using a steam engine for farm water would have been prohibitively expensive and pumped far more water than is necessary.
The hydraulic ram allows pumping water from a low place to a higher place without the use of external energy, neither steam nor (though not discovered at that time) electricity.
Whitehurst apparently invented an early hydraulic pump in 1772 but failed to patent or commercialize the technology.
Later, in 1796, Montgolfier perfected the hydraulic pump and worked with Boulton to commercialize it.
Montgolfier was the co-inventor of the hot air balloon, along with his brother. Boulton is the partner in Boulton & Watt which, at this time, has a thriving business in steam pumps. Montgolfier worked on engineering and Boulton on legal and business matters.
Hydraulic rams were never a potential disruptor to steam (and eventually electrical) pumps. They were far less reliable and pumped far less water. However, though not especially useful in mining or industry, they were useful for farming. Their ability to pump a reasonable amount of water without any external power source led to higher yield crops and an ability to grow crops in areas that were previously too dry. Electric pumps largely displace hydraulic pumps for farm water though, in especially remote areas where there is no power source or in areas where power is expensive, they remain in use.