don’t plan on letting myself get to the stage where I have to rely on others to end my life
Most people don’t, but many people who do find themselves in such an unfortunate predicament report they have a higher standard of life than anticipated and many that felt as strongly as you intimated change their minds when faced with this for real.
Also, do you have a spouse or dependent children that would rely on a life assurance payout, enhanced pension or death in service payment from your work to help them? You may forfeit these is you go down the Switzerland route.
I agree there should be a choice. (edit) not in any way criticising your views just adding comments to emphase that it’s a difficult choice and a potential political minefield.