Absolutely baptism is commanded for believers.
It just doesn’t save them.
And yes, our own works. Because if baptism were a work of God, given by God for salvation, then the OT Law, also qualifies as that. The OT Law was given by God so that would also qualify as the works of God. And they don’t save. No reason to think that any additional works save.
The reason they don’t save is because we already broke the law and it’s not a matter of judging our good works vs bad works and seeing which outweighs the other.
The wages of sin is death and THAT is the penalty that has to be paid. Without the shedding of blood, there is no forgiveness of sin. Without the death of Christ, satisfying the justice of God, there is no forgiveness. And forgiveness is the ONLY way to have that debt removed.
Water baptism wets the body but cannot touch the soul or the spirit, and physical religious works, activities, duties, whatever, do not cause spiritual reality to happen.
If water baptism saved, then it would save regardless of whether the person believed or not. If it were to bring about spiritual reality, it would HAVE to work, all the time.
Jesus plus anything means that you (plural) are trusting the other thing cause you (plural) don’t think Jesus alone is enough to save. So the person who is trusting Jesus plus baptism/communion/works is relying on the baptism/communion/works and not Jesus because in their minds, Jesus alone is inadequate.
The WHOLE church didn't write that 'requirement' in it's letter of instruction found in Acts 15.