To add on to this: it is important to not engage with their bad habits. If they send you a link to reddit or Instagram or tiktok, don't look at it and don't react to it. If they ask about it, "oh yeah i don't use reddit anymore". Even say you've blocked it for your own mental health.
Theother person may need to choose between you and the content. Their choice may hurt, but it needs to be made.