Okay no. This “varies” copout and amount of deflecting just to try arguing against the upgrade is starting to get ridiculous now.
I don’t know why people think psychic from the Lake Trio wouldn’t have them put their own power into the move when psychic is making use of their own energy, just as it does for any user of the move. But even IF the arguments of them only combining High 7-A attacks had any kind of merit behind them (which, given this form of Heatran was completely unphased by that combined attack, makes this already an unlikely option), one could also very much just argue that the Lake Trio playing a supporting role here in and of itself is a proof of this form being on the same level as them. Why take the more complicated route of going through so much more extra steps, including the intervention of Arceus itself, if the Lake Trio on their lonesome could handle this Heatran? A Heatran that, again, was empowered by an object from a being immensely more powerful than the Lake Trio by considerable leaps and bounds?
Again people, the Lake Trios part in all of this isn’t even the only thing to look at here. Again, Arceus himself came in to intervene, which wouldn’t be necessary if this form of Heatran wasn’t that big of a threat. And the form is getting all of the work done using Arceus’s own plate on top of that.
And it’s interesting that earlier it was mentioned Cynthia saying that Arceus wants people and Pokémon to be able to solve their own problems without getting involved so much, but yet the small but important detail that was left out or conveniently ignored is that Arceus always watches everything that happens and will only provide them a hint to solve issues if there’s nothing else they can do on their own. Which, including that small detail, can also be another proof that sided with Heatran getting the upgrade when considering the Lake Trio were actively involved in this debacle longer than Arceus and the latter still took it upon itself to intervene in the matter. Which wouldn’t be a necessary thing to do if the Lake Trio by themselves were able to help Ash and the others to finish the task without Arceus.