That is never going to happen. Anyone whose "solution" requires that the world adopts their religion is merely posturing They are not looking for a solution to anything.
Yes, they don't have a workable, practical solution.
How would they solve the war in Ukraine? They'd have all the other nations of the world rise up against Putin and Russia.
The war in Gaza? Who are they going to fight? For both sides, the enemy is mixed in with innocent civilians.
But Baha'is don't believe war and killing is the solution. So, what are they going to demand the opposing sides do?
The Baha'i solution is to have a grand "World Tribunal". If people or countries have a problem, take it to the Tribunal and let them decide. Both sides would have already agreed to abide by the decision. And if they don't? The Tribunal would force them?
So long as these prejudices [religious, racial, national, political] survive, there will be continuous and fearsome wars.
To
remedy this condition there must be universal peace. To bring this about, a Supreme Tribunal must be established, representative of all governments and peoples; questions both national and international must be referred thereto, and all must carry out the decrees of this Tribunal. Should any government or people disobey, let the whole world arise against that government or people.
(“Selections from the Writings of ‘Abdu’l-Bahá”, p. 249)
It's like this thread... The solution to "us vs. them" is for all of the people to love and accept each other. Yeah, that would work. All Baha'is have to do is get people to love and accept each other. But right here on this forum and in this thread, Baha'is can't even do that.
So, the solution depends on us agreeing with them and to "heed" the councils of their prophet, Baha'u'llah.