That is the "For You". I have a comment on this story about how you can remove it, and there are plugins out there that remove it.

Once it is gone Twitter becomes usable again – you only see who you follow and ads. Otherwise it is a really awful experience.

Loser Lane

Oh nothing much: Mailpit is installed via a script and then we added a systemd unit vs 'gem install mailcatcher && mailcatcher'

We used to use MailCatcher, and it worked quite nicely, but then switched to Arm machines and it broke. So we are using Mailpit https://mailpit.axllent.org (which also nice, but more complicated to setup).

Looks like MailCatcher fixed the Arm issue – maybe we will switch back.

You can disable "For You" and only have your timeline and lists.

But you need a plugin (or run some javascript). I am trying to get a Safari Extension through the App Store... but that is taking some time.

    (function() {
        var defaultMatch = "For you";
        
        function fixYou() {
            let firstSelected = document.querySelectorAll('[href="/home"][aria-selected="true"]')[0];
            let text = firstSelected.textContent;
            
            if(text == defaultMatch){
                document.querySelectorAll('[href="/home"][aria-selected="false"]')[0].click();
            }
        }

        const observer = new MutationObserver((mutations) => { fixYou() });
        observer.observe(document.body, { childList: true, subtree: true });
        window.addEventListener('load', () => { fixYou(); });
    })();

This is the code to do it, if you want to roll your own.