Da`wah: An Obligation?

Asalamu alakum.I am asking in the context of India where Mushriks are majority.Why Scholars interprit Dawa as Fard Kifa?Verse is3:104which says a group among Muslims should do duty.But3:110says everyone has to do duty,means Fard Ain.Now 9:71 also says everyone including women not some.So3:104maybe interpreted wrong as Scholars can make mistake,as it becomes a contradiction when at 2 places says everyone has to do & one place say only some has to do.Some Scholars did interprit 3:104 as ?by you?instead of ?from amongst you?.Tafseers also say3:104 was revealed in Medina after establisment of Islamic state when duties where divided to groups to do Dawa,establish prayer,Zakat collection,civil,defence etc.Then there is no contradiction.Mecca is similair to India though not 100%.Who can deny that if any Sahaba did not do dawa to Mushriks?infact for 13 years?It was In Medina duty divided.Some say we need ilm & then nobody does dawa giving excuse we have no ilm.All we have to say is about Allah,Prophets/Quran &its Message /Hereafter.Did Siddique,Umar,Ali have deep ilm initially?Definitely we must learn (12:108) but also do Dawa as when we converse to Mushriks we are encouraged to learn more to make Islam superior.We recite Iklas everyday.Proclaim He Is one,He has no son. Muslim believes so.Mushriks are idol worshippers believing in more than one god and Christians believe Jesus(peace be on him)as son of God.We are surrounded by these Mushriks..Is this only 4 recitation or also 4 preaching?Islam is not mere theories.Many recite Surah Kahf on Friday but Verse 4 says Quran revealed to warn those whosay Allah has son.Who warns?but a few?Has time andCan learn about Fiqh matters&how to defeat all Muslim groups except his own which is only correct as in 30:32&create enemity,but no Dawa as it is Kifaya & support of Scholars so the excuse of no ilm & thus escapes responsibility.Enemies are smiling.Dear Scholars.Help.Was Salam.