yet I've seen some people documenting 5V trigger relays in their projects

Those are probably opto isolated relay modules that use 5V for power but the trigger voltage and amperage is much lower.

If you want to use your relay then you will need to step up the voltage. A level shifter is good if you are doing mutiple GPIO 5V outputs. Otherwise you can use a transistor and some resistors.

BTW I added Amazon links just as examples. I do not recommend buying from them due to quality control.