What about having 2 buttons vs 1 button makes something "inaccessible"? If anything having 2 buttons makes the options that are in the context of the current application more accessible.
But people are incurious, stupid, and just dull-witted, I guess? So you really want the rest of us to have to suffer with 1 button because the lower end of the bell-curve can't handle 2 buttons for reasons related to stupidity?
People who don't come to use a computer for the first time until middle age or later tend to struggle mightily. I'm not sure why, but they seem to have a strong aversion to experimenting with the system. I face this issue almost every day with my 74-year-old father and his iPhone. He can only do the tasks which I explicitly teach him and anything new (like changing a setting he's never changed before) requires me to show him the steps. The fact that changing a different setting in the Settings app is an almost-identical process never occurs to him. He just asks for help every time.
Back in the Classic Mac OS days he did just fine with a 1-button mouse. He was able to click on and interact with everything and got what he needed out of the computer. A 2-button mouse is just utterly baffling to him. It turns every single thing on the screen into a fork in the road: do I left-click this or right-click it?
My 72 year old mother installs her own video cards and has a mouse with 5 buttons. YMMV, I guess.
The 1 button mouse was not superior in any way, and the people that get confused by a mouse with more than 1 button probably should never look at a web page with more than one thing to click. Did your father ever drive a car? Is he aware there's more than one pedal and lever to use? Did he ever find his way to the windshield wipers or did you just drive around with the rain obstructing the view? I'm genuinely curious how such a person could function in this world in the last 80 years.
The pedals in a car always do the same thing every time you press them, in every car you get into. Mouse buttons are not like this. Different applications use them differently. There may be a sizeable chunk that are reasonably consistent but there are tons of outliers that do all kinds of bizarre stuff like using right click to select or to cancel an operation or to bring up a tool tip. Sometimes it’s left click to select and right click to move.
Plus you never know what’s going to be in a context menu until you right click to open it. Sometimes you move the mouse slightly and right click something else and get a different context menu. For an older person with declining vision this can be very confusing. Fixed menus at the top of the screen are discoverable. You can even search for what you want in the help menu. Context menus are not discoverable.
I’m glad your mother knows how to install video cards. My aunt worked at a TV factory installing boards into the case and soldering all the through-hole components to the board. She’s still pretty baffled by computers but she’s almost 80 years old and rarely needs them.
You have to be willfully ignorant or brain damaged to not understand how a 2-button mouse works after the first time using it. The context menu does different things depending on the context. Someone that can't understand that is seriously in trouble in life. It's not something that should be confusing at all.
And as I said, hopefully your father never visits any websites, because they are all different with information in different places on every website. The world must be an extremely frustrating and hostile place for someone that gets confused by a 2 button mouse. I honestly feel bad for your father if everything you say is true.
But people are incurious, stupid, and just dull-witted, I guess? So you really want the rest of us to have to suffer with 1 button because the lower end of the bell-curve can't handle 2 buttons for reasons related to stupidity?