Why is a disk mounted multiple times inside my docker container?

These are all the disks that appear as mounted inside the nextcloud admin panel:

My ssd partition nvme0n1p2 (where docker and Linux is installed) is mounted a total of three times in three different locations. I dont quite understand why that is and would like to know if it is possible for me to unmount the unnecessary ones (if they even are unnecessary of course)
All uploaded data resides inside sda1, see my docker-compose.yml:

version: "3.8"

volumes:
  nextcloud_aio_mastercontainer:
    name: nextcloud_aio_mastercontainer # This line is not allowed to be changed

services:
  nextcloud:
    image: nextcloud/all-in-one:latest # Must be changed to 'nextcloud/all-in-one:latest-arm64' when used with an arm64 CPU
    restart: always
    container_name: nextcloud-aio-mastercontainer # This line is not allowed to be changed
    volumes:
      - nextcloud_aio_mastercontainer:/mnt/docker-aio-config # This line is not allowed to be changed
      - /var/run/docker.sock:/var/run/docker.sock:ro # May be changed on macOS, Windows or docker rootless. See the applicable documentation
    ports:
      # - 80:80 # Can be removed when running behind a reverse proxy. See https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md
      - 8080:8080
      # - 8443:8443 # Can be removed when running behind a reverse proxy. See https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md
    environment: # Is needed when using any of the options below
      - APACHE_PORT=11000 # Is needed when running behind a reverse proxy. See https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md
      # - APACHE_IP_BINDING=127.0.0.1 # Should be set when running behind a reverse proxy that is running on the same host. See https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md
      - TALK_PORT=3478 # This allows to adjust the port that the talk container is using.
      - NEXTCLOUD_DATADIR=/mnt/WDBlue6TB/nextcloud # Allows to set the host directory for Nextcloud's datadir. See https://github.com/nextcloud/all-in-one#how-to-change-the-default-location-of-nextclouds-datadir
      # - NEXTCLOUD_MOUNT=/mnt/ # Allows the Nextcloud container to access the chosen directory on the host. See https://github.com/nextcloud/all-in-one#how-to-allow-the-nextcloud-container-to-access-directories-on-the-host
      # - DOCKER_SOCKET_PATH=/var/run/docker.sock # Needs to be specified if the docker socket on the host is not located in the default '/var/run/docker.sock'. Otherwise mastercontainer updates will fail.
      # - DISABLE_BACKUP_SECTION=true # Setting this to true allows to hide the backup section in the AIO interface.

  # # Optional: Caddy reverse proxy. See https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md
  # # You can find further examples here: https://github.com/nextcloud/all-in-one/discussions/588
  # caddy:
  #   image: caddy:alpine
  #   restart: always
  #   container_name: caddy
  #   volumes:
  #     - ./Caddyfile:/etc/caddy/Caddyfile
  #     - ./certs:/certs
  #     - ./config:/config
  #     - ./data:/data
  #     - ./sites:/srv
  #   network_mode: "host"

Fstab file of the docker host:

# Static information about the filesystems.
# See fstab(5) for details.

# <file system> <dir> <type> <options> <dump> <pass>
# /dev/nvme0n1p2
UUID=5ec776d1-0720-47ab-a5e5-307c1ec54620	/         	ext4      	rw,relatime	0 1

# /dev/nvme0n1p1
UUID=DA3F-DBAA      	/boot     	vfat      	rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro	0 2

# /dev/nvme0n1p3
UUID=d1cd0629-e07f-4405-a587-88ca6c75b6fa	none      	swap      	defaults  	0 0

###########################################

UUID=142d4030-2f3b-41db-b936-d0b9eecfb0fd  /mnt/WDBlue6TB ext4 defaults 0 0

This is something docker does by default without anyone having control about it. See e.g. How to disable /etc/hosts /etc/hostname /etc/resolv.conf mounts with docker run ? 路 Issue #41229 路 moby/moby 路 GitHub

As for the /mnt/ncdata and /var/www/html mountpoints, these are indeed directories that are mounted from your host into the container by AIO automatically.

Also see hide /etc/hostname and /etc/hosts mounts by szaimen 路 Pull Request #388 路 nextcloud/serverinfo 路 GitHub