i get that this claim is usually smooshed in between different claims that are more deeply thought out, but the whole “mike only liked el for her powers” never felt like an argument that matched the original goal for mike’s character.
in season 1, when the show’s core ideas were at their strongest, mike is shown both as an empathetic friend who wants to find will and as someone who connects to and gives shelter to el when everyone else was unable to.
going to the “adults” would mean el being afraid that the same thing would happen to mike’s parents as what happened to benny. mike took her at her word without pushing because he intuitively understood that there was trauma there. which is, like, remarkably emotionally intelligent for a little boy at that age. i think people are forgetting how incredibly empathetic and gentle he was in season 1. he was able to see el as a person who needed help, which is reinforced in many scenes, and also simultaneously understood the urgency of the fact that el’s knowledge or abilities could help save will. he loved all of his friends, el included. she saved both him and dustin and he valued that on a really serious level.
like, he made the connection that what el brought to the table could help find will and he was reasonably urgent about that. considering the genre, the kids ignoring the adults and plunging forward into danger was always going to be the MO.
when he thought she was lying, both when will’s fake body washed up and when she was caught messing with the compass, he had emotional reactions because he felt lied to and he wants to save will. he’s a scared little kid, at this point. but he was the first one to realize he had gone too far and that el was probably just scared too. he put that together and fought to find her. he also let el still stay in his home even after will’s body initially turned up. it wasn’t just about finding will for him— el was his friend now, too.
even when dustin wanted to make her float things, mike scolded him for treating her like a dog. he didn’t want to make her use her powers. there was never a heavy emphasis on him liking her powers specifically. it was more that he understood el was bringing tools to the table to help their missing friend, and he knew that in solving whatever was happening, that would also benefit el. like, the boys didn’t have the same adult realizations hopper was having at that moment where he thought that the government was kidnapping and enslaving children for experiments, but they seemed to basically have a sense that that was more or less what was happening and that it was a problem. again, mike was emotionally mature for his age.
whether or not that continued to be the case in the following seasons is an entirely separate conversation that involves subjective opinions, but the assertion that mike only liked el for her powers or that he had any particular focus on her powers is kind of like an overblown reading of the plot building/structure of s1 that ignores a lot of the things that made mike a good friend and character, in my opinion.
and i don’t have to say this, but i will: the double standard that it’s suddenly cute if mike appreciates will’s power/ability to save them but that it’s somehow not cute or even toxic if that same thing happens between mike and el… it’s misogynistic at worst and confusing at best. there could be some arguments for how mike was all el had at first, so mike even conceptually admiring her powers or asking her to help them with will is unfair and el needs independence. i would also say that the show agrees with you there, because they do give el a home and things outside of mike. el’s situation was not a good one to be in. she was traumatized, alone, and pretty consistently suffering. but they were both children when will was missing and it seems like a disingenuous reach to call what happened toxic. i would even say it kind of ignores the tropes and genre in a way, too. here are two tropes you can read about on tv tropes to familiarize yourself with why things played out this way (hint: it’s not because mileven is toxic or because they’re trying to plant seeds that mike doesn’t actually like el):
and, then, to top it off, you have the speech where mike specifically says he loves her without her powers. whether or not the show has ‘good’ writing is another conversation, and you’re within your right to personally not find that they sufficiently showed how these characters connected outside of plot events, but what i’m trying to say is i think the intent (again, whether or not that landed for you is a different topic) was that mike is a good friend to all of them and there was emphasis on him worrying about el even outside of her helping will or anything even tangentially related to her powers. he formed a bond with her because he was empathetic to her in ways that were specifically unique for a boy at their age. so, in my opinion, the claim that he only cares about her powers does not feel like it holds much water.