Is Airbnb looked down upon here? Is there cheaper options when traveling around japan?

I was reading some recent threads on hotels vs airbnb all the airbnb posts were downvoted and alot of ppl reccomended hotels. Problem is, hotel prices have skyrocketed 300% or more since even a few years ago. I read of many residents can't even afford to travel in Japan cause the hotels cater to tourists prices. Eventhough I'm american I'm still pretty poor, but I wanted to travel through japan with 10K USD saved up and get cheapest accomedations for a few months. I was hoping to get rooms for 50$ a day or under, or even 30$ or under if possible lol is airbnb my best option or is there even better options that are cheaper? Maybe some that are just a room + air conditioner and I can go bath at an onsen for 1000 yen or something any tips or suggestions? I wonder how locals travel nowadays lol