The purpose was an exchange of ideas, to encourage one another, renew friendships with long lost friends and relatives, to praise God and much much more. Do you have a fear of public places or do you have something against the structure dedicated to the assembly?
The standard opening line for SDAs is “What’s the correct day of rest and worship in the Bible?” The sabbath was a day off, not a day of collective worship. Yet they’re using that gambit because they’re wanting people to come to their collective worship on Saturdays.
I have no problem with collective worship, but where were the people who were commanded to keep the sabbath told to “go to church” to observe it?
Let me put a little finer point on it. What the Jews were told to do on the sabbath was to stay in their homes (Ex. 16.29) and remember the sabbath in this fashion: “And thou shalt remember that thou wast a servant in the land of Egypt, and Jehovah thy God brought thee out thence by a mighty hand and by an outstretched arm: therefore Jehovah thy God commanded thee to keep the sabbath day.”
Yet SDAs, very fine people, don’t stay in their homes, and they don’t remember that God brought them of Egypt miraculously. Instead, they “go to church,” which God never told the Jews.