Don't show the accessibility icon when font size was tweaked
Nowadays many platforms solve the scaling problem more or less the same way:
- Provide an overall scaling factor that supports simple fractional scales (100%, 125%, 150%, etc)
- Provide a font scaling factor to further fine tune
For example, the ideal overall scaling factor for my screen would be about 140% (wrt to a 96dpi base), so I set it to 125% and then go to Tweaks and tweak the font size. I do something similar in Windows 10 or in Plasma (although both platforms allow to set 140% directly, for none of them it's a "recommended scale"). In MacOS I believe you just have the overall control with very few (three?) options, but their hardware range is also very limited, so that's the reason it works.
So far so good. The problem I see with GNOME Shell is that it insists in seeing this as an accessibility setting. This has two implications: there is a permanent icon in the topbar, and if you toggle "large text" off from it then your setting is reset and will resume at 125%.
Now, this is arguably no more of an accessibility matter than the overall scaling factor. I understand there is a blurry line here, but one thing is to set your screen currency wrt 96dpi gold standard and another thing is, once your screen is tuned to honor the geometry and proportions the developer intended, to be unable to properly read the standard sized text because you're a bit shortsighted or have been far too many sleepless hours in front of your screen.
Moreover, the fact that toggling the control resets and forgets your setting is also problematic. IMO this toggle should be a quick toggle with a predefined zoom level over the configured base level. That is, almost what it is now, but independent of what I did in Tweaks.
A further argument is that the variance in dpi is becoming high, with all sorts of screen sizes and resolutions, so this font fine tuning over simple overall scales will probably become more common, and a future in which most GNOME installations show an accessibility icon seems weird to me.