From what I have seen from this latest round of Covid is that it is pretty weak. More like a cold but it does zap your energy for 10 days or so.
I had it in May, and my energy was zapped for a day or two. By day 3, I had 70% of my energy back, day 4 95% back, and day 5 completely 100% back. I don’t think I ever got to less than 40% of my energy drained. I never stayed in bed other than the 8 hours I normally get. I will say that I didn’t feel like doing much, but did sit in my family room and watched the birds out the window, and read, instead of gardening. On day 3, I danced as I cooked dinner, I felt so good! Maybe I’m younger than some here, or maybe I’m in better shape, but it was just an annoying allergy-like cold for me.