Tampermonkey scripts with chatgpt is even faster. Adding a functionality to a website just by pasting the site's html in chatgpt and in 2min I get what I need.
Making a simple tool for a site or two is the perfect use case for a userscript manager like TamperMonkey/ViolentMonkey (FOSS alternative), I think making your own extension is somewhat overkill
Easier to share with others, too