Like I said this functions fine, as is evident by it having been posted, but the question was why it wasn't a very good repeater not was it a functional use of an existing pi 0 laying around.
It's also not the best you could do buying new if that is what you had to do as ~$16 will get you a 2x2 802.11n repeater that functions much better, has external antennas, and has an ethernet port too. Not $10 but it's also enclosed and doesn't need a power supply or uSD. ~$30 will get you decent AC repeaters you could use outside of a singular IoT project. Less for either if you're willing to go used. The ideal 4x4 ax double phy wireless repeater is indeed going to be more than a pi 0 but it was an example of what makes a repeater good (to the question) not what should have been purchased for this project.
Again nothing wrong with the solution used here, that's not where my comment was pointed.
I imagine the OP's use case of IoT did not require huge amounts of bandwidth.