The perception you don't need to use more force than necessary is very subjective. And trying to describe the act of firmly inserting the magazine leads to a choice of words that may be misleading.
Is the slide open or closed? It's going to take a lot more force to insert a mag on a closed slide than an open one. In that regard, it will feel like slamming the magazine in, compared to just sliding it in and having it click. The stack of cartridges has to compress against the spring. If it wasn't tall enough to need to, then the slide wouldn't catch the top round to chamber it.
That's where some confusion comes in - if the gun is loaded against a closed slide or bolt, then expect high effort.