A person who does these things might not be intentionally manipulating another in order to form a trauma bond.
Anyways, I learned that love-bombing, future faking, and idealization isn't always about manipulation. The person who does these things is most likely trying to find validation in themselves. People who do these things early in the connection most likely had very critical caregiver (parents) or partner. Nothing they did was ever good enough. They were heavily criticized and belittled just for being themselves. They were told that nobody else would accept them or put up with them. At some point, they may have started to believe this about themselves and told them self that that is the reason nothing every works out for them. Therefore, they tend to have very little faith in relationships. They view relationships as a heavy burden and a lot of work.
Therefore, when they meet a new person, especially one who shows interest, they will go overboard with the lovebombing, future faking, and idealization of that person. Seeing the other person get excited and respond with interest, attraction, and have a positive reaction is very validating. It makes them feel like, "hey, I'm not a bad person like my parents told me. I can be lovable, unlike what my ex made me feel."
This type of person also tends to make sacrifices and grand gestures for a toxic partner, and not because they love or are even in love with the partner. It's because the partner has made them feel so unworthy about themselves that if they perform these acts of services, they can prove to themselves that they're a good person. The irony is that the less toxic a partner is, the less acts of service they perform and the less interest they show.
In other words, this type of person always tend to perform, invest, and commit to a person who will create an imbalanced or toxic relationship. They do it to prove to themselves that they're lovable, worthy, and not worthless. Therefore, inadvertently sabotaging connections with the people whom they should keep in their lives.
One might conclude that they're a victim of abuse (either by parents, someone important in their life, or a partner).