At the end of the day everything is a judgement call. In this case I believe you're an outlier, guidelines are usually structured for the general case. Should you specifically treat every cold like it could be COVID? Maybe not, but should somebody else who gets sick only 1-3 times a year treat every cold like it could be COVID? That seems a lot more reasonable.
Not to mention it is wise and courteous to stay home and avoid exposing yourself to lots of people when you are sick regardless of if its COVID or not.
Not everyone can afford to stay home with minor illness. Not everyone will be employed if they stay home and can't "cover" their days off with measly 40 hrs a year of paid time for such purpose ( if they have any paid time at all).
This issue existed long before COVID. COVID is spreading partially due to this issue. Many people have no choice but work to avoid homelessness and/or hunger.
Not to mention it is wise and courteous to stay home and avoid exposing yourself to lots of people when you are sick regardless of if its COVID or not.