Keep the yellow cards, but change what you use them for. They are a bad treatment and a genuinely good measurement.
Write the date on each card when you put it out and replace it weekly. What you want is the count going down week on week, and that number tells you whether the thing you changed worked: which is otherwise impossible to judge, because "there seem to be fewer" is not something anybody can assess honestly about flies in their own house.
The other reason to keep them: they show you which pot. Put one card per plant rather than a few around the room, and after a week the distribution is usually lopsided. Often one pot is producing most of them, and it is nearly always the one with the densest, peatiest compost or the one that sits in a decorative pot with no drainage and never really dries.
That pot is worth dealing with separately. Repotting the worst offender into something with more drainage, and checking that no pot is standing in water in its cover pot, is frequently the single change that ends it.