Why does 5G require millions of small cells?

FR2 coverage Cell typesMax. number ​of users5G NR FR2Pico cell64 to 128Micro cell128 to 256Metro cellmore than 250Wi-Fi (for comparison)fewer than 505G – Wikipedia en.wikipedia.org › wiki › 5G

The reason for this expected growth in 5G small cell technology is because millimeter wave signals – the gold standard of 5G connectivity – don’t travel very far, and can’t penetrate walls, therefore making small cells vital for in-building coverage .18 Şub 2021

One FCC commissioner recently estimated that the US needs 800,000 small cells to make 5G a reality. International Data Corporation (IDC) expects over two million—by 2021.