Email keeps working because it is the only major channel where the connection between you and the reader is not rented. A social platform decides who sees your post; a search engine decides where your page ranks. An email address, freely given, is a direct line you keep even when every algorithm around you changes.
You own the list, not the platform
If a social account is suspended tomorrow, the audience goes with it. An exported list of subscribers moves to a new sending platform in an afternoon. That portability is the practical reason to treat email as the hub of your marketing and other channels as feeders into it.
It reaches people on their own terms
A subscriber reads when they open their inbox, not when a feed happens to surface you. That makes email suited to anything that needs attention and sequence: a multi-part lesson, a launch with several steps, a reminder that must land before a date. Nothing else in your stack can be scheduled with that confidence.
What email does badly
Email is poor at reaching strangers and at discovery. It will not create demand that does not exist, and a list built from people with no real interest performs worse than a small engaged one. Pair it with channels that find new people rather than expecting it to do both jobs.
Action Step
Open your analytics and your sending platform. For your last five social posts and your last five emails, write down how many people each reached and how many clicked through to your site. Keep the two tables as your own baseline to compare against in three months.
This lesson is educational and reflects general practice. Results depend on your situation, market and effort; adapt what you learn to your own context.