Just for weighted opinion:
I use my knives allot in various scenarios and just like various flashlights suit different peoples EDC requirements so to will knives:
I could write volumes about what knives I use for what purpose but the question was EDC.
EDC in an urban environment for me is my Leatherman Wave which has both a straight edge and a serrated and both get a good workout but generally the straight edge does most of the cutting but when I do need a serrated the straight will not be nearly as efficient.
EDC in a field environment (non tactical) I also like LedTed carry both a multi-tool (another LM Wave) plus either a folder or a fixed blade.
Generally it will be a folder (unless I am predominately hunting)
Unlike most views (which are relevant and also based on preference) I have to say a combo edge is my preference but with stipulations.
I spend allot of time in the field and I need about a 4 inch blade to accomplish most tasks but I am often restricted from carrying a fixed blade in some circumstances. I consider about 4 inches to be the minimum length for a combo blade to be effective. Any smaller and combo edges do become somewhat impractical for my purpose.
60% of my cutting in the field is rope and cordage, 20% splitting wood & tinder preparation and 20% food preparation (I know I should use a different knife for food prep but I am still alive and well after 50 years)
Currently my Field EDC is a CRKT M21 combo edge (with reworked straight portion). If I have the need for a very fine edge straight (narrow blade) I will use a scalpel from my FAK.
I have been in many circumstances when a straight edge (even a very sharp well prepared blade) has struggled to cut:
Reinforced Radiator hoses, Hydraulic Hoses, Braided Hoses, Hardwoods when preparing snares/traps, Kernmantle type ropes (notably in emergencies and trying to cut on a rock face), Bones, Slicing crusty field cooked breads and numerous other substances that escape me at this moment.
But in favour of the straight portion of my EDC it is ideal for lever cutting through banding, both metal and plastic, fine cuts to soft woods, most food prep, map preparation (cutting and contact application in the field), using as a chisel and another host of purposes.
I would dearly love to always have a knife for every purpose at hand on all occasions and if I am within walking distance of my 4x4 or my home I will generally have the correct knife but for EDC it will be a combo edge for me.
Sorry to all you knife purists out there (I really do love & appreciate a well prepared straight edge) but not for my EDC.