The Gedolim are great in Torah, you’re right. But gadlus in Torah, shteiging abilities, and finding innovative chakiras to explain a machlokes between the Rosh and the Ritva does not translate into political prowess or knowledge of world affairs.
When Rav Moshe z”tl had a question about the kashrus of certain fish, he asked a scientist to explain the relevant inyanim to him. In ancient Israel, the kohen and the king were two separate figures.
Once the gedolim start being mekadesh Shem shomayim, I will fully support them and all their decisions. Make no mistake, I respect their Torah learning and halachic decisions, but that doesn’t mean they know best about politics or science ( see slifkin). Rav Moshe understood this. They should too.