Cannot access internal phone memory through terminal or shell

I have a Samsung A5 (2017) with android 8.0 and while using the termux application and/or the shell command through adb I noticed that after running df -h I get this result:

Filesystem Size Used Avail Use% Mounted on
rootfs 1.2G 9.3M 1.2G 1% /
tmpfs 1.3G 1.0M 1.3G 1% /dev
tmpfs 1.3G 0 1.3G 0% /mnt
tmpfs 1.3G 0 1.3G 0% /mnt/secure
/dev/block/mmcblk0p19 4.5G 4.1G 435M 91% /system
/dev/block/mmcblk0p20 193M 3.9M 189M 3% /cache
/dev/block/mmcblk0p25 24G 21G 2.5G 89% /data
/dev/block/mmcblk0p3 16M 2.9M 13M 19% /efs
tmpfs 1.3G 0 1.3G 0% /storage
/data/media 24G 21G 2.5G 90% /storage/emulated
/mnt/media_rw/27FF-4487 59G 3.5G 56G 7% /storage/27FF-4487

Now I can guess that both /dev/block/mmcblk0p25 24G 21G 2.5G 89% /data AND /data/media 24G 21G 2.5G 90% /storage/emulated are the same and this is where the phone memory is mounted. Not sure why I see 2 different mounts for the same drive but that's not really the point here.

What I am really interested in is why I cannot access by doing ls any of those locations

ls /data
ls: /data: Permission denied

ls /storage/emulated
ls: /storage/emulated: Permission denied

By using the "My Files" application I can access the contents of "My Files > Internal Storage" and everything else that's inside. I assume this location it's the same as those 2 shown by the df command so why I cannot access them via shell?

If possible, an overview of all the other mounts shown by the df command would be appreciated as would shed more light on the android mounting system.

The mount command shows this:

rootfs on / type rootfs (ro,seclabel,size=1306380k,nr_inodes=326595)
tmpfs on /dev type tmpfs (rw,seclabel,nosuid,relatime,mode=755)
devpts on /dev/pts type devpts (rw,seclabel,relatime,mode=600)
proc on /proc type proc (rw,relatime,gid=3009,hidepid=2)
sysfs on /sys type sysfs (rw,seclabel,relatime)
selinuxfs on /sys/fs/selinux type selinuxfs (rw,relatime)
/sys/kernel/debug on /sys/kernel/debug type debugfs (rw,seclabel,relatime)
none on /acct type cgroup (rw,relatime,cpuacct)
tmpfs on /mnt type tmpfs (rw,seclabel,relatime,mode=755,gid=1000)
none on /config type configfs (rw,relatime)
tmpfs on /mnt/secure type tmpfs (rw,seclabel,relatime,mode=700)
tmpfs on /mnt/secure/asec type tmpfs (rw,seclabel,relatime,mode=700)
none on /dev/cpuctl type cgroup (rw,relatime,cpu)
pstore on /sys/fs/pstore type pstore (rw,seclabel,relatime)
/dev/block/mmcblk0p19 on /system type ext4 (ro,seclabel,noatime)
/dev/block/mmcblk0p20 on /cache type ext4 (rw,seclabel,nosuid,nodev,noatime,journal_checksum,journal_async_commit,noauto_da_alloc)
/dev/block/mmcblk0p25 on /data type ext4 (rw,seclabel,nosuid,nodev,noatime,journal_checksum,journal_async_commit,noauto_da_alloc)
/dev/block/mmcblk0p3 on /efs type ext4 (rw,seclabel,nosuid,nodev,noatime,discard,journal_checksum,journal_async_commit,noauto_da_alloc,data=ordered)
tmpfs on /storage type tmpfs (rw,seclabel,relatime,mode=755,gid=1000)
adb on /dev/usb-ffs/adb type functionfs (rw,relatime)
/data/media on /mnt/runtime/default/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,multiuser,mask=6,derive_gid,reserved=20MB)
/data/media on /storage/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,multiuser,mask=6,derive_gid,reserved=20MB)
/data/media on /mnt/runtime/read/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,multiuser,mask=23,derive_gid,reserved=20MB)
/data/media on /mnt/runtime/write/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,multiuser,mask=7,derive_gid,reserved=20MB)
/dev/block/vold/public:179,33 on /mnt/media_rw/27FF-4487 type sdfat (rw,dirsync,nosuid,nodev,noexec,noatime,nodiratime,fs=exfat,uid=1023,gid=1023,fmask=0007,dmask=0007,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,utf8,namecase=0,adj_req,symlink=0,bps=512,errors=remount-ro)
/dev/block/vold/public:179,33 on /mnt/secure/asec type sdfat (rw,dirsync,nosuid,nodev,noexec,noatime,nodiratime,fs=exfat,uid=1023,gid=1023,fmask=0007,dmask=0007,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,utf8,namecase=0,adj_req,symlink=0,bps=512,errors=remount-ro)
/mnt/media_rw/27FF-4487 on /mnt/runtime/default/27FF-4487 type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,mask=6,derive_gid)
/mnt/media_rw/27FF-4487 on /storage/27FF-4487 type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,mask=6,derive_gid)
/mnt/media_rw/27FF-4487 on /mnt/runtime/read/27FF-4487 type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,mask=18,derive_gid)
/mnt/media_rw/27FF-4487 on /mnt/runtime/write/27FF-4487 type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,mask=18,derive_gid)