Good morning slimboyfat
The answer would probably be along the lines: who else has proclaimed Jehovah's name around the world? Who else teaches who Jesus really is, the Son of God, and how he gave himself as a ransom for mankind? Who else tells people the message that Jehovah plans to restore the earth to a paradise for obedient mankind? Who else tells the truth about what happens when you die? Who else has love among themselves and will not take arms up against each other if they happen to live on opposite sides of borders? Other groups may have some of these truths or be so small they have splintered from the truth. Only JWs proclaim all these truths around the world. It is on the basis of having identified these core truths that the GB can be said to be being used by Jehovah to lead his people in these last days.
A problem with this list is that it is a selective list of what the watchtower does, and then treats it as a touchstone for others. We have already spoken on another thread "Praying for the death..." which shows the kind of spirit they have resorted to - and I have shown form the scriptures that the fear-inducing centuries-long preaching of imminent Armageddon cannot possibly be true - yet you still do it. Given these things, exactly how can you claim to be being led by God?
There is a better way... let yourself be led by God, and leave behind those things which are so clearly at the opposite end of the spectrum.