Portable AC exists and people do use it, but it's loud and awkward with casement windows. This is a bandaid solution at best. Yet, I've seen them sold out in the summer, so people do use them.
Not a whole lot more? Mounting a 40kg external unit on the facade of a building on the 5th floor is nothing to you? And that's after you get a permit to install it on the facade, which you will likely not (depending on the country).
If you have a balcony, you can mount the external unit there, but then you need to route the piping to the room(s) that need AC. Then you need to cover the pipes somehow, which is still perfectly doable, but goes way way beyond "drilling a hole".
You can have a portable unit, but it's loud, takes up space indoors and needs to be stored somewhere most of the year when it's actually cold rather than super hot.
I tolerate heat well, I feel very comfortable at 28C but I get cold easily. My sister is happy at 18C and starts overheating at 25C. Not everyone is the same.
That's not the only thing required to properly install an ac unit. Do you genuinely believe people die rather that drill a hole? Lile that's the blocker? What a weird take