As a web dev, I fully agree with this, but with a huge exception: clickable text. Anything that is meant to be read as content should absolutely, without fail, be selectable and copyable (assuming appropriate permissions). But stuff like tab headers, buttons, or even text-sparse tiles - things meant for the user to click on - can, and usually should , prevent text selection. It is super annoying to be clicking back a…
It's always bothered me that links on webpages are single click to open. They should require double clicking to open (like just about everything else on a computer) and single click should be used to start selecting text, like everywhere else on a computer.
The real problem IMO is that we have effectively standardized on two-button mice as the baseline, with all UX then designed around that even though many mice have 5+ buttons these days. The three basic actions that desktop UI has ultimately converged on are: select; activate; show additional actions (context menu). These should logically map to three independent buttons, such that the two most common actions are mapped to buttons that have fingers resting on them in neutral position - e.g. left = activate, right = select, middle = context menu.