dude. then re-write the documentation and present a draft here :D thats like saying canon takes better pictures than nikon. :D
I'll quote the man-page:
"DIFFERENCES TO APT-GET(8) The apt command is meant to be pleasant for end users and does not need to be backward compatible like apt-get(8). Therefore some options are different:
· The option DPkg::Progress-Fancy is enabled. · The option APT::Color is enabled. · A new list command is available similar to dpkg --list. · The option upgrade has --with-new-pkgs enabled by default.
also, to be helpful, the packages you mentioned all have installation candidates in Ubuntu 18.04. and if you don't already have an appropriate version of openssl, there are plenty to choose from, including vanilla. "openssl" you may need to update your apt sources if you are not seeing them. the php files you referenced are part of the php7.2...