An android phone is outdated .Like all brands there is
No more security patches.
No more Operating system updates.
If it still requires updates then follow the instructions
Disable OEM by going through developer options.It will directly turnoff all security restrictions from first (Your phone is not receiving any security patches so these restrictions are not of any use now)
Now try to search through web for finding custom roms of most trusted companies .
Some examples:-Pixel,Linux, Microsoft etc
Install them on phone and activate.
You will experience those UIS on your phone+There will be no harm to device as they are equipped with security patches for whole life .