The video by Alex Jones from Guardian Tax Consultants explains why cash flow is critical for privately held businesses. He emphasizes that cash flow is essential for operations, growth, and sustaining enterprise value. Taxes are highlighted as both a liability and an opportunity to increase cash flow through proper planning. He walks through the business lifecycle, from startup to maturity, showing how cash flow grows with sales, profit, and reinvestment. Strategic tax planning is seen as a key tool for managing cash flow throughout these phases.