“Why?....It will propagate all by itself!...........🤦♂️”
No, apparently it won’t....since it hasn’t for the past ten years.


Are we talking about the same plant?
From BRAVE Summerizer AI:
Trumpet vine (Campsis radicans) is a native North American plant with glossy dark green elliptical leaves that grow up to 15 inches long, with seven to 11 serrated leaflets. It has clusters of trumpet-shaped red, orange, or yellow flowers that appear during the summer months and reach around 1 to 3 inches long before giving way to bean-like seed capsules.
Trumpet vine is often cultivated for its attractive, reddish orange flowers but can escape cultivation, sometimes colonizing so densely it seems a nuisance, particularly in the southeast, where its aggressive habit has earned it the names Hellvine and Devil's Shoestring.
The woody perennial vine can take over a yard in a single season in the warmest, wettest places, growing 30 and 40 feet tall and covering trees and fences faster than you say “Damn that invasive plant!” If you're not vigilant, trumpet vine can escape your yard and choke out other plants in the surrounding landscape. With adequate care and pruning, trumpet vines can be kept under control.