Is It Possible To Beat Minecraft With Only ONE Inventory Slot?

hi this is a video where steve from the famous mining game minecraft decides to not break the laws of physics too much for once by not bringing his very spacious magic backpack into his adventures
[EDIT: English subtitles are now available!]

[Music used]
C418 - Subwoofer Lullaby
C418 - Aria Math
C418 - Dreiton
Rhododo - buildingmusic.mp3 (since some of you asked, link: https://youtu.be/5xnXIsdx8bk)
Rhododo - bossawaiting.mp3
Rhododo - blazehomemusic.mp3
Rhododo - pianooutromuffled.mp3