I will say, though, disposable vapes with microcontrollers inside (and even full games and screens from recent reporting) are an egregious source of e-waste. Many layers of stupid are present here.
Islam is in fact the largest religion (by worshippers) in the world today, so Frank Herbert's assumption that a culture derived from it would be dominant in a future society is just extrapolation.
One reason is that the number of Christians in Sub-Saharan Africa is growing. But extrapolating the trends, yes Islam will probably become the largest religion in the coming decades.
Or at least maybe - looking at birth rates, it seems as second generation muslim immigrants to Western countries have even lower birth rates than the native population. That might happen also in regions say like Pakistan and Indonesia and other fast growing regions, depending on economical or other changes.