I have presented Biblical arguments and so have the folks who wrote the articles on those sites. Most of those folks previously attended the SDA church so they know first hand about their errors. Its typical that you refuse to seriously consider the truth and instead you present a persecution complex. I read how SDA's have institutionalized deception and also how they have a persecution complex in this article below:
https://www.nonsda.org/study12.shtml
In regard to Ellen G White, I find it interesting how she said she saw a
halo of glory around the Sabbath commandment in the Most Holy Place of God's temple in heaven and that the
Sabbath is a sign of Christ's power to make people holy, and that it will be a point of decision in the last days.
She also said the mark of the beast, symbolizes the celebration of Sunday – a false and idolatrous Sabbath. This spiritual sign will be activated in a future eschatological spiritual battle that will take place in the matter of worship and faithfulness to God’s commandments.
It's no wonder that SDA' s teach that those who worship God on Sunday instead of Saturday will receive the mark of the beast, which is ludicrous!
https://www.nonsda.org/study8.shtml
That false teaching, which has turned the sabbath day into an idol, is a stumbling block to believing the gospel.