pear/pecl are more for installing extensions TO php in my experience, where composer is for installing packages built IN php, so composer is more the defacto co

pear/pecl are more for installing extensions TO php in my experience, where composer is for installing packages built IN php, so composer is more the defacto community package manager, pear/pecl are useful though when you need to install gmp, gdi, intl, etc on your local dev environment. I don't know anyone who uses pear to install carbon or guzzle, or any other php package though.