> Globals, function names, massive pieces of code right in the middle of HTML, shell_exec.
And they're not inherently bad.
PHP made the internet fun. Anyone could get going with a PHP enabled host with by creating an HTML document starting with <?php> and have a working something that the world could see by end of the day.
Today's web development feels like such a drag. In that you need to choose the scaffolding, create the scaffolding, wait for the concrete to dry, drill holes for the infrastructure and then construct the infrastructure.
When you then go to connect the infrastructure you find that one of the girders has buckled which requires a patch-up or refactor. Someone's misprinted the blue-prints and the cable ferret has gotten lost down one of the connectivity holes. You then discover that a new scaffolding company has come to town so your construction is now obviously out of date.
PHP enabled you to have something cool in days. Nowadays you spend days just trying to setup react. my two cents.