For human - machine interaction devices such as keyboards, mice, game controllers, and graphics tablets, the transmission requirement is less than 1Mbps, and USB 2.0 bandwidth is more than sufficient. Its ultra - low power consumption (<100mA) perfectly matches the power supply needs, and the cost is precisely controlled (with packaging chips costing <$0.5). It creates a stable and economical connection solution for daily office and entertainment interactions, ensuring that operation commands are transmitted efficiently without delays or freezes.

In the field of basic office peripherals, including dot - matrix/inkjet printers, scanners, and card readers, the demand for high - speed SD card reading is low (<20MB/s), and the amount of print command data is small (KB - level). USB 2.0 can easily handle these tasks. Meanwhile, the service life of these devices is as long as 5 - 10 years, and USB 2.0 has stable compatibility, eliminating the need for frequent interface iterations, ensuring the continuous smoothness of office processes, and reducing equipment replacement and maintenance costs.

In the case of audio devices like USB microphones, entry - level sound cards, and computer speakers, 16bit/48kHz audio streams only require 1.5Mbps. USB 2.0's synchronous transmission mode achieves ultra - low latency, and it can supply power without an external power source for devices with <100mA power consumption. This simplifies the deployment of audio devices, ensuring smooth sound collection and playback, and is suitable for personal creation and entertainment listening scenarios.

For low - cost IoT devices such as smart sockets, temperature and humidity sensors, and RFID card readers, the module cost of USB 2.0 is as low as <$1 (while USB 3.0 chips cost more than $3). The protocol stack is extremely simple (with MCU resource occupancy <10KB), and it can be used immediately without driver installation, helping developers quickly build the perception layer of the Internet of Things, reducing the threshold for IoT deployment, and accelerating the implementation of smart scenarios.

For the maintenance of traditional equipment, including old - style cameras, barcode scanners, and medical equipment interfaces (stock devices produced from 2000 to 2010), USB 2.0 can be compatible for connection without the need to modify the original cables (Type - A direct connection). There are sufficient maintenance spare parts, prolonging the service life of old devices, ensuring the normal operation of legacy devices in fields such as healthcare and logistics, and saving equipment replacement costs.