I really like the idea of a package/dependency manager. It just seems that when ever I am reading a tutorial and they want to import something that is not standard they say write this in to your TOMOL not cargo install it. Like when reading python docs they all say to use pip or something. Sorry it just seems that Cargo is somewhat overlooked or is it just my perception?
cargo add <dep>is a relatively new command. For a long time you had to edit the Cargo.toml file to add a new dependency. So a lot of tutorials still use that as a way of adding a dependency. And other guides often copy from the older ones. They also can describe it this way as a way to introduce the Cargo.toml structure since it is not hard to hand edit.cargo addis just a convenience after all and it is still worth understanding the Cargo.toml structure.But yes, many people do use
cargo addfor simply adding deps rather than editing the toml file. Though it is not uncommon to edit it by hand either.