Another case of the browser doing what the OS and Desktop environment should be doing. I like to point at tabs - DEs and GUI toolkits never really came up with a good way to handle multiple documents well.
Widgets would be a potential solution but they keep being tried and abandoned soon after in desktop OSes.
In Mac Os one can use spotlight with cmd + space with similar results.
Or sometimes I check a calculator I implemented myself (shameless plug: https://getcalculator.app/)
Once again, compared to it just being there in front of you and ready to go that's still work to do to get it there.
You can do it all as one big expression with parentheses and such but if you're doing a bunch of calculations on the go that could get repetitive, and one wrong Esc and your calculation goes away.
There's still a calculator widget for the MacOS notification center. It's accessed in any app through a trackpad gesture or by clicking on the date/time in the menu bar.
The fact that it seems to be similar enough to the iOS implementation of them gives me hope, but only barely.
You also need to know the feature exists (they had notifications before widgets, people might not know it was updated to support them), that there exists a calculator widget, and to add it before you need to use it. That's the same discoverabiloty problem, with the added wrinkle that functionality changed in Monterey.
For most of the past decade. I believe widgets were added to Notification center in 2014.
Dashboard was first, and then they were reimagined as iOS-style in Monterey.