When you need to slow down and soft-land a spacecraft, you need to consider

1. How heavy is the craft?
2. How fast will it be going when you try to stop?
3. Will anything else be supplying stopping power? (i.e. a rocket motor above the payload)
4. How heavy is the gear doing the stopping? (has to be offset with fuel)

In 2015 NASA ripped a large supersonic parachute

The 100-foot-wide (30 meters) parachute — the biggest such chute ever deployed — unfurled well and apparently inflated fully, or nearly fully, Monday (June 8) before being ruptured by the fast-rushing air during the second flight test of NASA's Low-Density Supersonic Decelerator (LDSD) project.

Of interest is this quote

"On this project, we're pushing the limits of our technologies, our engineering and our understanding of aerodynamic decelerators," Clark added. "This year, the physics of supersonic parachutes pushed back on us."

From the linked article about the ESA parachute woes

 

Europe's 35-meter parachute in a 2018 test in Sweden. It will be the largest ever on Mars.

You'll note there's a 5M difference in the two parachutes. Why? NASA elaborates on that in general on another project (emphasis mine)

The design of the parachute is driven by "loads" (the forces the parachute experiences as it fully inflates). Loads are calculated by using atmospheric density, velocity, parachute drag area, and mass. The 2003 parachute design is part of a long-term Mars parachute technology development effort and is based on the designs and experience of the Viking and Pathfinder missions. The parachute for this mission is 40% larger than Pathfinder's because the largest load for the Mars Exploration Rover is between 18,000 and 19,000 pounds (80,100 - 84,600 N*) when the parachute fully inflates. By comparison, Pathfinder's inflation loads were approximately 8,000 pounds (35,600 N*).

Given that we're custom building spacecraft, it makes sense that agencies would custom make parachutes. If you try to make a one-size-fits-all parachute, you're limiting the size of spacecraft, and potentially over-sizing the parachute (and adding needless weight) to smaller craft. I do expect that, as we gain more experience building them, there will be more standardization, but for now, spacecraft are still esoteric enough to warrant custom parachutes.

When you need to slow down and soft-land a spacecraft, you need to consider

1. How heavy is the craft?
2. How fast will it be going when you try to stop?
3. Will anything else be supplying stopping power? (i.e. a rocket motor above the payload)
4. How heavy is the gear doing the stopping? (has to be offset with fuel)

In 2015 NASA ripped a large supersonic parachute

The 100-foot-wide (30 meters) parachute — the biggest such chute ever deployed — unfurled well and apparently inflated fully, or nearly fully, Monday (June 8) before being ruptured by the fast-rushing air during the second flight test of NASA's Low-Density Supersonic Decelerator (LDSD) project.

Of interest is this quote

"On this project, we're pushing the limits of our technologies, our engineering and our understanding of aerodynamic decelerators," Clark added. "This year, the physics of supersonic parachutes pushed back on us."

From the linked article about the ESA parachute woes

Europe's 35-meter parachute in a 2018 test in Sweden. It will be the largest ever on Mars.

You'll note there's a 5M difference in the two parachutes. Why? NASA elaborates on that in general on another project (emphasis mine)

The design of the parachute is driven by "loads" (the forces the parachute experiences as it fully inflates). Loads are calculated by using atmospheric density, velocity, parachute drag area, and mass. The 2003 parachute design is part of a long-term Mars parachute technology development effort and is based on the designs and experience of the Viking and Pathfinder missions. The parachute for this mission is 40% larger than Pathfinder's because the largest load for the Mars Exploration Rover is between 18,000 and 19,000 pounds (80,100 - 84,600 N*) when the parachute fully inflates. By comparison, Pathfinder's inflation loads were approximately 8,000 pounds (35,600 N*).

Given that we're custom building spacecraft, it makes sense that agencies would custom make parachutes. If you try to make a one-size-fits-all parachute, you're limiting the size of spacecraft, and potentially over-sizing the parachute (and adding needless weight) to smaller craft. I do expect that, as we gain more experience building them, there will be more standardization, but for now, spacecraft are still esoteric enough to warrant custom parachutes.