But the price increase kinda is a symptom of the underlying issue. For reference, the reason that subway subs were $5 for a long time was that the company was trying an advertising campaign to grow the brand, which it did amazingly well (honestly, far too well). However, those were not sold at a sustainable price, but whenever the company tried to raise the price it was perceived very poorly by the market. So they kept the price low for a long time, and eventually had to raise it but due to inflation (and decreasing the sub size to compensate for the low price before that), but the price increase was pretty drastic to most of the customers who often stopped going there.

In other words, the company kept the price down artificially to keep their stock price high, and foisted a lot of the actual costs onto the franchisees, of which they had tons. Which is obviously not a sustainable business model, and it's why less people go to subway anymore.