[blueimp]

Any Framework (including WebdriverIO) that uses the W3C Webdriver API or the older Selenium JSON Wire Protocol requires the appropriate driver for each browser.

In my opinion that's not a disadvantage, since the Webdriver API is a W3C standard and there are official drivers for each browser, implemented by the Browser vendors themselves (with the exception of the IEDriver, which is implemented by the Selenium project as far as I know).

Unless you use a built-in browser automation API (like Webdriver / Puppeteer), the only alternative is to inject the test code via JavaScript, which might pose problems with the Content-Security-Policy directive and often requires the tested site to run in an iframe, which poses additional problems.