Not sure how much is age... I notice that reading my phone is often harder than desktop. I usually have a set of reading or computer glasses with me, but don't need them except for things that are close. Stuff on the phone always seems a bit small. Maybe there should be an effort to consult designers over 40 on some of these web sites/apps.
HN, Google, DDG and Wikipedia (the mobile version is nicer) are the ones I can't use without setting to 125%.
[0] An upside of the mobile first trend?
EDIT: Eh, scratch that. Just noticed Github (125%) and Twitter (110%) are also on the list ¯\_(ツ)_/¯