You can do this for popular sites yourself, using JS and/or CSS:

.post-layout a[href^="https://stackoverflow.com/q"]::before {
    --size: 18px;
    
    content: '';
    display: inline-block;
    height: var(--size);
    width: var(--size);
    aspect-ratio: 1 / 1;
    margin: 0 2px 0 0;
    vertical-align: middle;
    background-image: url(https://cdn.sstatic.net/Sites/stackoverflow/Img/favicon.ico);
    background-size: var(--size) var(--size);
    background-repeat: no-repeat;
}

You can do this for popular sites yourself, using JS and/or CSS:

.post-layout a[href^="https://stackoverflow.com/q"]::before {
    --size: 18px;
    
    content: '';
    display: inline-block;
    margin: 0 2px 0 0;
    height: var(--size);
    width: var(--size);
    vertical-align: middle;
    background-image: url(https://cdn.sstatic.net/Sites/stackoverflow/Img/favicon.ico);
    background-size: var(--size) var(--size);
    background-repeat: no-repeat;
}