The biggest problem is the writers (any writer for that matter) starts in a tight spot for writing Boruto. How can you write a battle anime/manga about a fresh character (i.e. a character that starts from scratch or near scratch so they can progress throughout the story) while having literal gods walking around? There are way too many OP characters in the beginning of Boruto, how can they give Boruto meaningful fights (fights that have a lot on the line) if any of these people can wrap up the fight while eating their lunch? You either need to make your OP characters start to job and act like idiots, make your fresh character extremely OP from the start and just keep adding powers or making them more OP throughout the story, somehow limit the OP characters, or a combo of all of that. Boruto used the last one which made the story really bad from the start. Now Naruto who fought for 3 days straight, gave chakra to thousands, can make thousands of clones that last for days and fight kages, while he was teen can't make 1 clone for his daughter's birthday and is always exhausted. And when he gets hurt, ahh he was rusty and forget how to fight, or is trying to get information by getting beat (because he forget he has ninjas that can read minds) and then forget and actually did get hurt for real, or acts like an idiot and not use any of the jutsus he has to get hurt. Sasuke is always out of chakra and his rinnegan does nothing except open portals. He can barely even use his EMS now. Now that would have been bad but tolerable, but they made Boruto extremely OP from the start able to use rasengan right away, multiple chakra natures, speed and strength to fight high level jonins, and a new eye power/curse mark to make him take down kage+ opponents with ease. Now, if you read the manga, they limited the OP characters as well in a very shitty way as well.

So of course poor Konohamaru is getting that treatment. Him getting sage mode would only serve to show the enemy able to beat a sage with ease to show how terrifying the enemy is. Or best case scenario for him it would be to teach Boruto how to use sage mode.

Kishimoto stepped in recently, but I don't know how he can pick up the series from where it is at. He has to somehow kill Naruto to follow the opening panel/scene or somehow retcon it, while having to deal with writing aliens that are somehow stronger than Kaguya but still can be defeated by Boruto.