Soap bubble fruit is a strange thing. It looks like a bubble because it doesn't grow from any plant and has no anatomical structure. It seems that the whole point of its existence is to be eaten. The reason why plants produce fruits is to attract animals to feed and spread seeds. The fruits we see today are all artificially cultivated, and their volume and taste have been greatly improved.
Soap-soaked fruit has no seeds, which is equivalent to losing the goal of fruit existence and the goal of all biological adaptors-reproduction. We cultivate seedless fruits artificially, either through grafting or cutting (such as grapes and oranges) or through its seed parents (such as watermelons).
Maybe soap bubble fruit is not a fruit at all? It takes hunger and penance to get it, and it only accepts sincere and grateful people. This is a bit like the "manna" that God gave to Israel in Exodus. Mana appears with dew, like frost, and has no obvious biological characteristics. The whole meaning of its existence is to be eaten, because it is a gift from the gods, not a product of biological evolution.
Why soap bubbles are so focused on being eaten. Aphids and scale insects do take care of diners and provide "easy-to-eat" honeydew. This is also to attract devout followers. Many ants establish friendship with insects of Hemiptera. Aphids without ant companions will "squeeze out" honey dew and throw it away. Sugar-containing honey dew is very easy to breed mold, and it will pollute the environment if it is placed in its own place. Aphids who take care of ants will slowly discharge honey dew, which has bristles at the end of the abdomen, so that honey dew drops can be hung on it for ants to drink. If the ant can't come in a short time, it will even suck the honey dew back into the body and provide it later.