This is an hiv prevention forum, not a place for laymen to try to get a biology degree in hiv transmission.
But the good thing is that the 40 year old science is not dependent on you understanding it or being "convinced" as you put it that it is a fact.
Viruses, in general, are less virulent outside of a body for any period of time because, unlike bacteria, they require a human host in order to replicate and thrive. Here's an article by a physician explaining various scenarios: https://www.healthline.com/health/how-long-does-hiv-live-outside-the-body#bottom-line
Note the bottom line: "In fact, except for sharing needles and syringes, there has never been a documented case of a person getting HIV from casual contact with infected fluid on a surface in the environment."
In 40 years of observation, no one has been infected by fluid outside of the body.
I concur with CurfewX and would just like add, the reason contained infected fluid in a syringe would be able to have the virus retain it's infectious ability because of vacuum or no interference with environment. In a nutshell, once the virus is exposed to the environment it's outer shell that protects the caspid protein starts disintegrating causing it to be uninfectious.
Practically, the virus gradually starts degrading it's infectious ability the moment it establishes contact with the environment and can't infect because of low potency and ineffective transmission routes.
Therefore, HIV has limited survival chances outside host environments, and typically must transfer directly from host to host.