I wouldn't be absolutely sure about this. In the end, everything on the web still boils down to (mostly) simple HTTP GET requests. If you open a webpage, then you are served the file you requested (usually HTML with CSS for styling and JavaScript for special actions) and your browser handles the display of them and the execution of their scripts. This means that you can program a browser to detect and remove ads directly from the code and also eradicate malicious detection scripts potentially employed by Google that are meant to find out whether the ads are displaying correctly. If Google would want to circumvent this, they would either have to make YouTube available solely over their own app or block such behaviour on the client's end, for example by manipulating the browser's code to block ad-blocking functionality. Google is actually pursuing the latter with their Chromium browser, which is also the foundation for some others, including Microsoft Edge. This is why it's important that people start to move away and use Firefox for browsing, THE free/libre software non-profit web solution since decades. Because then Google is essentially powerless, if they don't want to take YouTube off the web.