Rented versus owned: the difference that decides everything
A follower is a rented audience. The platform sits between you and them: it decides how many people see your post, when, and in what order. Organic reach has collapsed in recent years, often down to a small fraction of your followers, and it swings hard depending on the platform, the format and the moment. Do not trust a general figure: look at your own stats and you will see the gap between your follower count and your actual views.
An email is an owned audience. You hold the address, you can export it, and you reach the person when you decide, with no intermediary filtering. If your account gets suspended or restricted tomorrow, or the algorithm changes the rules, your list is still there. It is the only part of your audience that cannot be taken from you. The rest you are only borrowing.
The operator's reasoning fits in one sentence: use platforms for what they are good at, discovery, and move every interested person onto a channel you own. Views exist to fill the list; the list is what lasts.