Because wheat grown for Matzah (or rather vice-versa, wheat fields selected for Matzah) is monitored closely for moisture and perfect harvesting time, in addition to optimal storage and more precautions taken — especially Shmurah Matzah — mold that may be present in regular wheat/flour is not an issue. This may be an overlooked part in regular bread/Challah that people may have issues/intolerance from. It’s also good to know when comparing to chometz’dig Matzah.
But it’s not a once size fits all cure, just something to experiment with — and don’t forget about yeast, eggs sugar etc. that are not included in Matzah.
Good luck, and may we all be well and feel well.