Earlier quoted context omitted.
Firefox has an override for that, shift+right mouse should ignore the click handlers and show the browser context menu. This is something I really miss in other browsers, especially the ones that decide that they know better than me about how things like copy/paste are supposed to work.
I have never heard this before. Is there more stuff like this? Note: I can't test this right now because I don't have any sites that do this particular bad thing
There are some other accessibility tricks that Firefox advertises [3] like ignoring website font and color choices.
Firefox also has native support for overriding website CSS [5] but "modern" websites often come with impossible to understand DOM and CSS structures (if they even use CSS and not just forcefully insert style into the DOM directly because separation of concerns is for losers I guess).
Then there are websites like Github and some shitty forum software that insist on hijacking keyboard shortcuts like Ctrl+F and Ctrl+K. You can go into about:config and set permissions.default.shortcuts to 2 (Services.perms.DENY_ACTION) to block websites from overriding shortcut settings by default. You can go into the site settings and manually enable them again by going to page info (ctrl+i), then tabbing over to permissions, and changing the value for "override keyboard shortcuts" from "default" to "allow". Or, you could simply block the websites that offend you from that screen without changing the default.
[1]: https://www.codeinwp.com/snippets/disable-right-click-contex...
[2]: https://codepen.io/impressivewebs/embed/zYYxepW?height=265&t...
[3]: https://support.mozilla.org/en-US/kb/accessibility-features-...
[4]: https://superuser.com/questions/318912/how-can-i-override-th...