Having worked in B2B marketing and sales teams for 10 years, I have seen the same issue across all businesses I have been involved in. The ambitions of the business leaders for marketing simply outweighs the budget available.
If marketing teams could consistently churn out fresh content without the financial burden and risk of hiring full-time designers, they'd be much more effective. This would enable them to engage a larger portion of their ideal customer profile with targeted, tailored content relavent them and their pain points.