You are. It's not subtitled, but he says it literally right before his line about Signora. I even gave you a convenient timestamp. Also, you can't just say that him saying he'll go all-out is untrue without any backing.
What you think is irrelevant to what's fact.
Do you not hear how angry he is? He literally says that the Traveler 'tricking' him is going to cost (the Traveler). You're also flat-out ignoring him literally saying "I'll go all out" and "I should take you seriously".
Pushing back? You realize that there are countless instances in fiction where a vastly superior character gets pushed back by a clash. What you're seeing is blatantly false. Childe isn't "pushing through the Traveler's attack with one arm". The Traveler is holding back Childe's attack with one arm. Childe attacked first.
And while we do see Childe overpower the Traveler, the gap in strength isn't nearly as wide as you make it seem to be. The fact that Childe's attack was held back at all should be enough to scale their AP with each other. We
can argue that Childe is more skilled, since he's famous for being a master in several weapons, but we cannot say that Childe has that much more raw power than the Traveler. Besides, when the Traveler backsteps to use a surprise Geo attack, while they do get blown back. This obviously did no damage to them, since they land perfectly on their feet and without being any worse for wear.
Paimon didn't say Childe was playing with them. Paimon said that Childe had played them, as in,
tricked them.
As for the Weekly Boss, remember that canonically, the repeatable boss fight is the Traveler's memories of the event, so we can easily assume that it's canon, one way or another. All we're getting is more context to the fight. Dialogue there can't be dismissed so easily.
Finally, I also explained exactly why I believe Childe was bloodlusted. He's raising his voice and lashing out. He gets pissed and violently slams the ground when he comes to the conclusion that you tricked him. He's shouting about how you'll
pay for tricking him ("Not bad. But this is going to cost you!!"). He's frantically trying to rationalize
how you managed to trick him, all while attacking you. He literally breaks through the floor for no reason after transforming. These are not the actions of a calm or playful person like you're implying he's being.
The biggest nail in the coffin? He KNOWS that the Foul Legacy Transformation has severe drawbacks on his body. He knows yet he
still used it. It can be argued that he's either forced to do so in the hopes of defeating the Traveler faster, or that he's just so angry that he doesn't care. Either way, Childe is going all-out, and the Traveler is fighting him. Whether they outright beat him or outlast his transformation doesn't matter. They're fighting a full-power Childe.
Ultimately, what matters isn't whether or not the Traveler is as skilled as Childe. What matters is whether the Traveler can
keep up with Childe. The Traveler can dodge attacks from a bloodlusted Childe in his strongest form. That's speed. The Traveler can hold back a finishing blow from a serious Childe for a decent amount of time. The strike was already held back. The only difference between them past the initial impact would be lifting strength. The impact itself was Childe's AP. The fact that the Traveler can face it head-on with their own attack means that their AP is roughly equal.
This isn't even taking into account that Childe, by his own admission, was unquestionably
forced to use his Delusion. The Traveler was strong enough to beat Vision-only Childe. That's a
fact. Remember also that Childe still uses his Hydro abilities in his later phases. That means that said Hydro abilities backscale from them if he expects said abilities to work at all. His Hydro arrows don't start moving faster or hitting harder just because he's using another element, after all.
To sum up, Childe was definitely serious by the time he activated his Delusion. You can't just dismiss his dialogue as if you're a more reliable source than the guy himself, and by extension, the writers. Childe was undoubtedly more skilled than the Traveler, but you're overlooking what's important about the confrontation that
actually determines scaling: the stats.
- The Traveler can dodge a serious, even bloodlusted, Childe. That's Speed.
- The Traveler can counter the force of a serious Childe's attack with their own. That's AP.
- The fact that the Traveler is injured yet not defeated means that they can tank a serious Childe's attacks. That's Durability.
I'm not arguing that Childe
wasn't superior to the Traveler; even though based on the weekly boss there's more than enough basis for it.
I'm arguing that Childe and the Traveler are roughly equal in
stats. Skill is an entirely different factor; being relevant only because we have to keep in mind that skill-stomps are a thing and that "losing" does not mean "inferior in strength and speed". The Traveler absolutely scales to Childe.