Comment by Gareth321

There are many browsers which come with native ad-blocking. See Brave, Vivaldi, Opera.

Most browsers are built on Chromium, and that has certain ad-block limitations now. See Manifest V3.

Many people care a lot about ad-blocking, but still, most of the world does not use an ad-blockers. So it's a cost/market reach equation. What's your target demo? If it's tech enthusiasts, we'll appreciate the ad-blocking built in, but we can also easily install one ourselves if it's built on Chromium.

You are unlikely to face legal issues. There have been a few test cases around the world, with most siding with the user. The argument is usually that no one should be forced to download or render something they do not wish to download or render.