The meme asked “Why didn’t the Fellowship just take a boat?”
Not for nothing, but I recall a lot of fighting men in Corsairs along that river that led up to Osgiliath.
"Why didn't the Fellowship just take a boat?"
That's facepalm stupid.
There's a hell of a difference between a river and open ocean. They'd need a big boat with sailors. Where would they get that?
They'd have to sail along a coastline that is sailed by the Corsairs you mentioned.
The river they'd have to sail has enemy country along one side the entire way. They'd be filled with so many arrows, or just downright sunk by heavy artillery.