You can add tremendious value just by publishing your research and linking to the sources, even if you have not added anything, those hours you spent searching - that your readers dont have to, and likely your readers dont have the same experience as you, so they wont be able to read the sorces critically. So by not adding anything, you can still save someone years of time.

There is also nothing wrong with serving good knowelage, even if you can find the information somewhere else. Maybe your source is 10 years old, what has happened since? Or maybe its hard to understand for laymen. Or maybe the other sources will fall off the web, great websites disappears in the thousands every day.

Maybe someone is looking for a tech, but there's little info out there, even if the i info is good, it can still be dismissed. Help spread the knowledge.

Then there's the noise to signal problem. Your blog will be a light beacon - for others to navigate around all the crap.

Coming from the guy who made the best biopic movie of all time, I would expect nothing less.

It also seems likely that that idea is also not novel, so that the previous poster wouldn't want to blog publicly about it.

You've gone too meta. ;-)