Why specifically was Obi-Wan Kenobi the "only hope" of Princess Leia?

I know that there is a sort of similar question about how Princess Leia knew about Obi-Wan here, but I'm curious as to why and how Princess Leia thought an aging Obi-Wan Kenobi would be of any help to the Rebellion worth risking herself and her crew in addition to the stolen Death Star plans (which apparently the Rebellion only had stored on R2-D2 physically, and no other copies)?

Things to consider:

1. Obi-Wan as a resource to the Rebellion didn't even have his own ship or own resources to contribute (not even enough to pay for passage for a smuggler to transport him).


2. Obi-Wan as a fighter did not do any extensive amount of fighting in A New Hope (he cut off a guy's arm in a bar, and sacrificed himself vs Darth Vader, that's it)


3. Obi-Wan as a Jedi didn't have an apprentice yet, and was probably not going to have a shot at taking on Darth Vader or the Emperor.

Possible answers I've considered (I'm curious for more though):

1. Obi-Wan might have some sort of wisdom or knowledge about attacking the Death Star and he may have been able to analyze the stolen Death Star plans for weaknesses (but the Rebels did a good job of this anyway).


2. Obi-Wan would have been exceptional at espionage and infiltration (took out the tractor beam on the Death Star, successfully avoided almost every stormtrooper he encountered, and Jedi mind tricked the ones he couldn't avoid -- think "these aren't the droids you're looking for"), although Obi-Wan's stealth would not have been needed inside the Death Star had Leia not gotten herself captured and in need of a rescue from the Death Star in the first place, which happened as a result of trying to visit Obi-Wan.