One possibility is that archaeamphora went extinct due to environmental changes. The climate during the Ediacaran period was very different from today. The Earth was much warmer, and the oceans were more acidic. These changes may have made it difficult for archaeamphora to survive.
Competition from other organisms
Another possibility is that archaeamphora went extinct due to competition from other organisms. The Ediacaran period was a time of great evolutionary change. Many new organisms evolved during this time, including animals and plants. These new organisms may have competed with archaeamphora for food and resources, leading to their extinction.
Disease
Finally, it is also possible that archaeamphora went extinct due to disease. Disease can spread quickly through a population, and it can be very deadly. If archaeamphora were infected with a disease, it could have caused their extinction.
It is likely that a combination of these factors led to the extinction of archaeamphora. The environmental changes, competition from other organisms, and disease all played a role in their disappearance.