I have yet to see a good argument as to why we can't just collect all of the world's trash, nuclear waste, and all other unwanted things and fire it all into the sun.

I found a Forbes article and it states these arguments which I still don't think are strong:
https://www.forbes.com/sites/startswithabang/2019/09/20/this-is-why-we-dont-shoot-earths-garbage-into-the-sun/

>The possibility of a launch failure. If your payload is radioactive or hazardous and you have an explosion on launch or during a fly-by with Earth, all of that waste will be uncontrollably distributed across Earth.
>Energetically, it costs less to shoot your payload out of the Solar System (from a positive gravity assist with planets like Jupiter) than it does to shoot your payload into the Sun.
>And finally, even if we chose to do it, the cost to send our garbage into the Sun is prohibitively expensive at present.

'too expensive' gets me. Still doesn't convince me.