Currently the gold weighs 0.5 kg per 1 Gold Coin, so if u have 50,000 gold coins that would weigh 25,000 KG, pretty much not possible to carry that around.
I understand that the current system may be in place to encourage players to place their gold onto an island due to the weight, but with the current state of the game, it's not really possible imo. I would have to attempt to steal territory in my PvE server to even build a base for my treasure stash, which is pretty hard due to companies spamming them everywhere and some1 always being online to contest it.