The Sabbath has a role to play at the end of time.
Very soon everyone will have to make a choice. Either for God and receiving His seal (by doing the will of the Father, keeping the commandments, and the faith of Jesus), or for Satan and receiving his seal (by not keeping God’s commandments, including the Sabbath, and receiving the Mark of the Beast). And then Jesus will return.
Below Isaiah describes what will happen at the end because man has changed the Sabbath from Saturday to Sunday and have transgressed His commandments and broken the everlasting covenant:
Behold, the LORD maketh the earth empty, and maketh it waste, and turneth it upside down, and scattereth abroad the inhabitants thereof.
Isaiah 24:1,3,5
The land shall be utterly emptied, and utterly spoiled: for the LORD hath spoken this word.
The earth also is defiled under the inhabitants thereof; because they have transgressed the laws, changed the ordinance, broken the everlasting covenant.
Daniel also describes the attempt to change the Sabbath from Saturday to Sunday:
And he shall speak great words against the most High, and shall wear out the saints of the most High, and think to change times and laws: and they shall be given into his hand until a time and times and the dividing of time.
Daniel 7:25