Paul’s instruction regarding the betrothed should not be taken as a moral command. It is meant as loving counsel, by which he wishes to spare God’s people from worldly troubles.
The phrase worldly troubles
is a good translation of a phrase that literally means tribulation in the flesh.
Especially in times of persecution (see 1 Corinthians 7:26), a married person will experience added troubles, due to concern for a spouse and children.
28 Si tu t'es marié, tu n'as point péché; et si la vierge s'est mariée, elle n'a point péché; mais ces personnes auront des tribulations dans la chair, et je voudrais vous les épargner.