Capybara still works. But the main downside of capybara is the debugging when something went wrong. You would need to start a test server and goes to the server to debug. Or pry into that test to debug the response html. Feedback loop is pretty long. There is tool like capybara-inline-screenshot that could show a screenshot of the failure pages to mitigate.
Recently there is Cypress. That enables you write JavaScript to interactively test your pages. As you’re writing the test, cypress reloads the page live to provide you visual feedback and super fast feedback loop. See the video on their website to get the ideas!
Install cypress-rails and follow the README.md. Justin Searls has figured out for you
Percy is more polished and used by many well known companies and there is SAUCELABS.