Earlier quoted context omitted.
FYI your font-size is uncomfortably huge, I can see maybe 25 lines of text on my desktop screen. It feels like I should step backward a meter or two.
Enormous fonts is a trend in modern web design for some reason. I browse most sites at about 66% zoom. Get used to the Ctrl+- shortcut.
Most designers do not work intimately with the content, so text is more shapes on the page than the main course. I do not mean this disparagingly, I have just seen a lot of designs in my time where the text is placeholder stuff in designs.
In reality text needs to be of a certain line length. If it gets too long then it can be hard to follow. Wall of text is a problem too.
The best way to do text is to make it proportional to the width of the browser window. If the lower font size is the 16px recommended by Google for accessibility then the maximum size can be what you might call enormous - on a 4K monitor. Everything can be just right in between.
If you do have a 4K monitor and you are using it for just one browser window then enormous is what you want - it will look good in the meeting room on a huge screen that everyone can see.
Some fettling of margins can go on too, so a small screen can have narrow margins, so 1rem on a phone and a lot more on bigger screens.
With these methods it is possible to make design a lot easier with everything proportionate to screen size. But if your designers are only thinking in terms of fixed with fonts and they produce the mobile and the desktop views with baked in font sizes that get signed off by the client then you are stuck with it.
It really is up to the design community to get with font scaling and to not be insistent on a couple of fixed font options.
This should be simple but in a multi-disciplinary team where most web design is then sausage-factoried with old layout hacks (so no CSS Grid or CSS variables) then progress is difficult if not impossible.