Trouble is, you live in a democracy. Other peoples’ opinions matter. You only have the rights that the majority gives you. And a constitution with a built in amendment method provides no absolutes. Here today is no more legitimate than gone tomorrow. There are no rights except those the majority agrees with...more or less. Taking unreasonable positions behind the cold, dead hands banner is in all likelihood not going to end well. It doesn’t have to be that way.
If you are talking about ordinary legislature not affecting constitutional rights, what you say is true. But what you say is actually rights depend on popular support--bollocks. There are far too many Supreme Court decisions that spit in the face of the majority and are not popular, may be unreasonable, and have caused great injustices. It would be more to the point to argue that disfavored rights of the elites are shoveled under and favored rights are celebrated in practicality. Nevertheless, the point does not hold in our system that rights depend on popular votes.
These and the fact that no revolution has yet begun indicate that actually we don't live in a democracy as pointed out above and your post shows little understanding of the nature of rights. They are not predicated upon "Democracy", a "King", nor a "Commissar". Natural rights exist apart from the political system and political systems are set up to protect rights (see social contract theory). Rights are not collective, so that people do not get to vote on who gets what rights and how much, they are individual in nature. Any such vote to limit someone's natural rights represents an act of tyranny--it is not legitimate even though it would be 99 to 1 which represents the bandwagon fallacy in logic in the extreme.
On the rest of it, I strongly suggest that you read the Federalist papers which explains the nature of each provision and why it is there.
For example,
You keep insisting on the amendment procedure as political but it takes 2/3rds vote of EACH House of Congress Plus 3/4 vote of both houses in the states legislatures (Nebraska only has one) affirming the amendment (38 states as of today). That is the nature of a republic where even the popular vote cannot take immediate effect (that is also why we do not have national plebiscites on issues). For that reason, very few actually go through because we are not a democracy (the last proposed successful one involved the right of 18 year olds to vote during the 1970's) --the small states get a vote too--not just the masses in California and New York. That is by design to prevent encroachments on rights.
For example, my 4th Amendment right against unreasonable search and seizure is not up for Congress, the executive, and the state legislature, or even the judiciary to abrogate. Any such action, despite majority approval, represents an act of tyranny.
Instead, your thinking in your post more closely resembles the medieval ideas where rights are subject to the ruler's whims. In your case, Democracy would be the ruling whim. The proper term for that is privileges which are established by law and may be set aside by another ordinary law. There is a reason the Brits rose up against King John and forced a Magna Carta that rejected the idea of rights being dependent on the rulers down his throat at swordpoint and had to reiterate it with various kings until the Glorious Revolution settled the issue in 1688 (as much as anything can be settled).
As a practical matter, I personally find bump stocks and even binary triggers as rather stupid ways of converting ammunition into empty brass. I also believe that these are designed on purpose to circumvent the NFA. On a purely personal note on constitutional law, I believe our current commerce clause jurisprudence to be a mess and an affront to the 10th Amendment and the idea that you can achieve (as did the NFA) the same results by using the taxing power of the government, I find to be a stretch. Recognizing, absent some cataclysm, that neither are likely to change in the near future at the Supreme Court, then the question becomes exactly what is a "machine gun" which is banned by current statute absent NFA registration (which under current law is impossible--thanks Rep. Hughes). Once again, because the Supreme Court is NOT going to overturn the NFA (see stare decisis) in the near future, then as a practical matter, constitutional challenges to the NFA and subsequent statutes won't get anywhere. That leaves whether or not the ATF's actions are a reasonable interpretation of its authority under firearms laws to restrict "machine guns". My prediction is that the courts will go along with that.
However, the massive numbers of these outlawed may result in a successful 5th Amendment challenge that could either grandfather these into legal existence through judicial fiat or force Congress to address the issue.