Is there a way to improve performance here using No Exists?
You can try to rewrite it as:

select * 
FROM followers_info finfo
WHERE NOT EXISTS ( 
    SELECT 1 FROM user_followers uf 
    WHERE uf.follower_id = finfo.follower_id
)
AND NOT EXISTS (
    SELECT 1 FROM user_following fing 
    WHERE fing.follower_id = finfo.follower_id 
);


or:

select * 
FROM followers_info finfo
WHERE NOT EXISTS ( 
    SELECT 1 FROM user_followers uf 
    WHERE uf.follower_id = finfo.follower_id
    UNION ALL
    SELECT 1 FROM user_following fing 
    WHERE fing.follower_id = finfo.follower_id 
);


Generally no better nor worse, but worth a try