Fill adds solid hard outline
Whenever I use fill it outright adds to whatever I'm filling like this


The above image has a soft outline but when I fill it it makes it bigger with a hard outline. If I were to keep on clicking fill it would simply get bigger and bigger everytime.
Selecting an area and then filling also gives me that horrid hard outline because it just fills the entire selected area. How would I just fill an entire shape whilst maintaining softness?


