The problem I encounter more frequently is: Advertised number is high %, then after considering all risks and terms and conditions it is sub average.

Decisions are about tradeoffs. 2% of users staring at a broken screen is bad, of course. But what is the _cost_ of not using nested CSS? The responsible way to make a decision is to consider both sides of the tradeoff.

> If a website uses fancy new browser features and works for 98% of the population, that means that it won’t work for ~150 million people.

Yes, because all of us have website serving, checks notes, the entire world...

98% is probably in the neighborhood of 8% more than I'd require for browsers compatibility before deciding to use a new feature. At a certain people need to update and we do ourselves and our other 98% of customers no favors by catering to the lowest common denominator.

See also, the story of YouTube adding a banner pushing people to upgrade off old IE version being a large factor in people upgrading. Now, obviously, we aren't all running YouTube-sized sites but building for ancient browsers is, very often, a large waste of time.

In the age of evergreen browsers you have to go out of your way to be using something that's not at most a couple years out of date.

The biggest thing missing from this analysis is "is there a business case for supporting those 2% of users?". (Maybe, maybe not.)

The second biggest thing is progressive enhancement. The author picked a CSS feature (nesting) that is basically all-or-nothing: the site will basically be entirely broken for those 2% if you swap Sass for native nesting. Most features aren't like that; maybe the site won't look pixel-perfect on old browsers, or one bit of functionality won't work, but by and large it will still be functional. In those cases, I think it's a much easier decision in terms of where to draw the cutoff.

I guarantee you, if your product is a mobile app, you're excluding more than 2% of the population.

In the early days of commercial optical-character-recognition software, vendors would brag about 99% accuracy.

But a single-spaced-typewritten page has about 500 words, so you were looking at five typos every single page. It was good at the time, but you still had to manually check every single word.

If 2 out of 100 people I know see a broken website, depending on the website, that's fine, that doesn't sound like a big deal. Now, if out of 10 power users, all ten of them see a broken site once every 50 logins? Thats a much bigger deal. 98% can be more than enough or not remotely enough depending on the units involved but there are plenty of cases where it's fine to not support the last 2 internet explorer users and stuff

Isn't this obvious?

In some categories, certainty and percentages make a lot of difference--surgeries, accidents. In some, they don't--surveys, grades.

It just depends on the category.

This is akin to saying something as obvious as more percentages are more than less percentages.

That reminds me of an old comic where a guy picks a milk carton from the grocery store shelf and reads in the box: "Now with 0.01% less semen." and he does not know if he's happy or sad about it.

That framing is setting the question so you immediately are forced to compare pears to apples.

Of course 98% of sterilization is not enough for surgery or for precision in calculating your account balance but the category of landing page conversion a 98% would be astronomically high.