People do things for shits and giggles all the time. SpaceX literally launched a model Tesla for absolutely no reason other than advertising both themselves and their sister company.

Doubly so if they can now become “the furthest man made object”. That’s massive free marketing.

It may also be exponentially easier to do so in the future, lowering the expenditure needed to make it happen.

It might not be reasonable right now, but, once again, the bar was set at always. That is an exceptionally high bar with very little reasoning behind it.

They absolutely had way more of a reason than no reason. Za reason for the Tesla launch was that it was the first falcon 9 heavy launch, and no company was willing to gamble that large of a payload on a untested rocket. So they made the best of it with a PR stunt.

They literally could have sent up anything and it certainly wasn’t useful, which was GP’s only criteria for being launched.