Many companies work only through Facebook or Instagram. It works — until it stops.
Four things that happen
Reach keeps shrinking. Years ago a post reached most followers. Now — a few percent, unless you pay.
The page can be closed. A false report, an automated decision, a hacked profile. People have lost pages with tens of thousands of followers overnight, with no explanation.
Google does not find you. Someone searching for "plumber Skopje" rarely lands on a Facebook page. They land on a website.
It does not look serious for big jobs. A company looking for a supplier checks you. If you only have Facebook, that raises a question.
That does not mean you should leave it
Social networks work well for what they are for — everyday communication, photos, quick news. But they are your street, not your shop. The street can be closed.
Both together
The website is the base — everything is there, permanently, and Google finds it. Social networks bring people to it. Whoever has only one of the two works with one hand.