I agree, in practice I see this occasionally on gigantic GitHub pull requests with 1000+ files, or very clunky Atlassian/Confluence pages. I'd say both sides need to work on their resource management!

(On that note, many complaints about Safari I hear from developers fall on my ears as "I don't care about web compatibility!" as it has never NOT been the case on the web that you need to care about feature support and resource management.)

I will also note that Safari is almost /too/ deeply integrated in the system, when I'm running a high-stress task elsewhere, my browser would jitter or hang, the same couldn't be said for chromium, for some reason.

Safari use less CPU power than Firefox, chrome being the worst of them all.

It's even more obvious when watching video where safari will be 5 to 10 points lower than Firefox.

Harder to say when it's rendering page but the fact of the matter is that I tried both for years, Firefox always drain the battery faster.

I use all three.

Safari loses out when you run with a lot of Tabs. Both Chrome and Firefox knows when to unload tabs. ( Firefox even have about:unloads to tell you the order of Tabs it will unload! )

Try opening Tab Overview in Safari and it will start loading all the website for thumbnails, paging out to disk due to low memory, writing hundreds of GB to page. It also put Tabs on low running priority in the background rather than pausing them like Firefox or Chrome. ( Not sure if that is still the case with Safari 26, at least it was with 18 ). To combat that, restarting the browser time to time helps.

Safari is well tuned for iOS as a single tab, single page usage. On MacOS when doing many tabs it start to get slow and inefficient. And this is very much a Safari issue not an Webkit issue because Orion is a lot better at it.

And yes I have filed Radar report for many of the issues but I have come to the conclusion Apple doesn't care about multi tab usage on desktop Safari.

I think the difference is fundamental to the engine and the gap will be hard to close, too (I mean, how long has it been and the gap remains?). WebKit-based ultralight browsers remain usable after you’ve cranked hardware specs down far enough that nothing based on Chrome or Firefox’s engines do. Resource use among the three engines seems to differ at some kind of low, basic architecture level.