The new Performance page will allow tech-savvy users to control how much RAM Firefox will be using. The more "content" processes Firefox will be allowed to use, the more responsive the browser will get, and the easier will be to handle tens or hundreds of tabs.
The downside is that more "content" processes means more RAM usage, but if users have RAM to spare, this shouldn't be a problem. It is a problem, though, on older systems. This is where the new Performance section comes to help, allowing users to put a muzzle on Firefox's unwieldy memory usage, preventing crashes or computer freezes.
[I]t will not always be obvious that it is an advert
Super-illegal over here...
There's nothing preventing you from running an agile project with a robust and complete design. Agility allows you to pivot if and when required.
The easiest way to think of agile projects is a series of really small waterfall-like mini-projects that deliver a working product at the end. As you complete each mini-project, your product comprises a larger set of features. When your feature set reaches MVP, you can release or continue iterating to complete more features, but you can feasibly release at the end of any mini-project.
All of the arguments I've seen around [Aa]gile have shown that both sides are unwilling to concede that they don't actually understand the others' points of view.
There is no project that can't benefit from the ideas agile project management introduces, and there's no rule that says you should throw away your working model to implement agile (although it is generally easier to start with a single team that does start from scratch).
ALL projects benefit from measuring the outcomes of small, incremental changes and continually finding and limiting waste.