A visitor makes a judgement about credibility long before they read your service list. Consistent identity across the website, ads and social profiles is part of that judgement.
Consistency also compounds attention. When your creative looks recognisably yours, repeated exposure builds familiarity instead of starting from zero each time.
The practical output is a system: logo usage, palette, typography and layout rules that anyone producing content can apply.
That system is what keeps a growing marketing operation from looking like six different companies.