What evidence is there that the ordinary JW “wants to preach so badly”?
I don’t see it. The ones I know in family are loving the break and seem to have forgotten their former routine. I hear nothing about the ministry, except cynical laughter when an elder dared to ask if they had a report.
Anyway , what benefits would a convert get? I have hardly seen a new one for years unless you count the lonely foreigner who was distinctly, ahem, mentally challenged.
Still, he would get , community, a sense of belonging, perhaps a faith, some Bible knowledge, perhaps a hope for a better future... Even though we can see that to be false.