This issue arises all the time, and I'm wondering if anybody has a solution to this Large Fonts issue, yet?
What older people are after is an equivalent to the Microsoft Windows "Large Fonts" setting, whereby all fonts including menu bars and Finder labels are automatically increased by a certain percentage, while retaining the optimum resolution.
2560x1440 is my optimum resolution. To get the text to default to what'd be a perfect size, I'd have to set the resolution to 1600x900.
There's no point in owning an excellent high resolution monitor if we have to fuzz up the fonts in order to be able to see what we are doing.
This is an obvious, long term accessibility issue and I'm at a loss to understand why Apple, an otherwise extremely customer oriented company, have not introduced an easy way for us to do this as the operating system has progressed through the various versions.