It should be an essential tool for all website owners - everyone should care about page loading time from the CEO down to the junior web developer. Page speed is a factor that hugely affects visitor satisfaction, and Google takes it seriously by offering PageSpeed Insights. If you work in a larger organisation and focus on one particular part of website development and maintenance, such as a content writer, then this tool won't be as useful. It's intended for users with development or marketing-related responsibility
This is an area where AuthorityLabs really shines. It's one of the few Martech or SEO tools vendors about whom I can honestly say I've never had a complaint about their customer support. The team there consistently responds to any questions I've had or issues I've encountered quickly, helpfully, and in a way that feels personal.
I've never used any software beyond PageSpeed Insights and Google Lighthouse (the source of the PAgeSpeed Insights software.) I've used similar programs like Hummingbird for WordPress that pulls the same data using the same engine, but its really the only game in town as far as I'm concerned.
On the plus side, for relatively small keyword tracking projects, AuthorityLabs costs less and is simpler to use than these tools. However, it is also much more limited. SEMRush or Serpstat are better options if you also need diagnostics, backlink analysis, simple brand monitoring, and other functions beyond keyword rank position tracking.