Telstra "delivered 5X data growth at fixed cost by FY21." That required productivity improvement of 37%/year. Verizon estimates 40%/year. CEO Vestberg puts it another way: "Our cost per bit is 1/10th of what it was." Deutsche Telekom estimates 1/8th. None of these figures are exact, but the trend is obvious.
Wireless technology is improving at a ferocious rate. As we all know, demand for bits continually increases. The improvements in technology have generally matched the growth in traffic demand. Now that traffic growth is slowing, overcapacity is likely.
The rough equivalence between capacity and demand is confirmed by the financial reports of Telstra, Verizon, and most other telcos. Capital spending has been flat while generally meeting demand. Speeds have gone up dramatically.
Supply and demand explain much of what's happening in telco networks.