My face looks dull these days. What could be the reason?

I'm worried because my skin tone looks dull and lifeless overall these days. I think I looked okay even without makeup in the past, but lately when I look in the mirror, my skin looks a bit dark and dull.

I have been consistently using basic skincare products, but I haven't noticed any significant changes. I also use face masks occasionally, but it feels like my skin improves only for a brief moment. I am wondering if there is a skincare routine I might be missing.

Are there any ways to make my skin tone look clearer and brighter, or easy skincare routines I can do at home? Please let me know if there are any methods you've seen results from doing consistently!