Those tiny virus particles are contained in the droplets, and the fewer you breathe in the easier time your immune system has in dealing with the ones you do.
That a mask can capture sneeze or spittle droplets is true, but only for a few minutes until those droplets begin to dry out. Then, unless you replace your mask that captured those droplets, like any dry filter the mask will begin to unload its particles -- specifically, the virus -- which will pass easily through the mask then deep into your lungs with every breath. Happy masking!
I can count on one hand the number of times anyone has ever sneezed on me. I would not choose to spend my life wearing a mask to prevent that.