The ESP-12F sits one step below the ESP32 family in capability, and that's precisely the point   for a large category of IoT projects, a single-core Wi-Fi chip is genuinely all that's needed, and paying for a dual-core processor with Bluetooth that never gets used is money spent on capability that goes to waste.

This is the bare module, not a development board, which matters for how it should be positioned: there's no USB port, no onboard regulator, and no breakout headers here. It's built to be soldered directly onto a custom PCB, where the designer's own circuit handles power regulation and provides a way to flash firmware typically through a separate USB-to-serial adapter during development, with that circuitry then either removed or left out entirely in the final production board.

Where it earns its keep is in genuinely simple, high-volume applications: a Wi-Fi-controlled relay, a basic sensor that reports a single value periodically, or a smart switch that just needs to receive an on/off command over the network. For any of those, the ESP8266's full onboard TCP/IP stack means it can run the entire Wi-Fi connection itself, without needing a separate microcontroller to manage it.

The honest recommendation split: if a project needs Bluetooth, multiple concurrent tasks, or more processing headroom, the ESP32 family is the better fit despite the higher price. If the job really is just "connect to Wi-Fi and do one simple thing reliably," the ESP-12F does that job at a lower cost, and this bare module version specifically suits anyone integrating it into their own board design rather than prototyping on a breadboard.