Comment by Lichtso

> but [analytic anti-aliasing (aaa)] also has much better quality than what can be practically achieved with supersampling

What this statement is missing is that aaa coverage is immediately resolved, while msaa coverage is resolved later in a separate step with extra data being buffered in between. This is important because msaa is unbiased while aaa is biased towards too much coverage once two paths partially cover the same pixel. In other words aaa becomes incorrect once you draw overlapping or self-intersecting paths.

Think about drawing the same path over and over at the same place: aaa will become darker with every iteration, msaa is idempotent and will not change further after the first iteration.

Unfortunately, this is a little known fact even in the exquisite circles of 2D vector graphics people, often presenting aaa as the silver bullet, which it is not.