I lost my sense of smell temporarily because of a Covid infection, and it was gone completely - I could stick my nose into a jar of ground coffee and not smell a thing. Funnily enough, they say that if you can't smell, your sense of taste is also impaired, but I could taste food just fine...
Had the same, but both taste and smell... anything eaten was just tasteless goo for maybe 6 weeks, no point in fine cuisine. I tested myself daily with sniffing a bottle of 52% home made slivovitz, it was like breathing mountain air, no reaction to even rather concentrated alcohol vapors.
Weird times... I'll never know if my smell came back 100%, or just some fraction of it. In fact, it took good additional 6 months to get my personal perfume to smell nice again, while normal smells kid of came back, this was a litmus paper for me that I am not 100% there yet.
Btw you can lose smell easily permanently, all it takes is 1 good hit in the nose. Nerves going through the skulls go through these tiny pores in the bone, and if the nose cartilage moves enough suddenly they all get severed/chopped. Doctors are quite familiar with this, no way to get this repaired.
