Why do fatwas prohibit emigration to Western countries, even though religious observance may be easier there, and why isn't emigration to Islamic countries easier? And how can Islam spread without emigration to Western countries? And is living in non-Islamic countries better than living in countries where hypocrisy prevails?

The majority of scholars do not prohibit residing in lands of disbelievers if one is safe from temptation (fitna) and able to observe the rituals of their religion. When these conditions are met, residence is permissible; if they are absent, it is not permissible except for one who is compelled. This varies depending on the country, circumstances, and individuals. The fundamental principle is that a Muslim's residence should be in Muslim lands, and the best place is that which aids in obedience to Allah and righteousness. As for the questioner's point about migrating to Western countries to spread Islam and for education, this might be said for someone who travels temporarily for da'wah (proselytization) or education, but not for permanent migration and residence, which are often for livelihood reasons. Moreover, means of da'wah and education are now available remotely. The main consideration is safety from temptation and the ability to observe the rituals of one's religion.