I think there are several external variables that might influence an individuals’ perceived ease of use or perceived usefulness of a new technology
Age and generational differences: People in different generations have experienced different paradigms of technology. This is an evident phenomenon nowadays. Younger people expects everything to be automated and they have a shorter attention span. This can be shown from the social networks that are popular amongst the youth, such as Tiktok and Snapchat. It shows that they don’t want the input output process to take long and they don’t like textual input. Meanwhile, the older generation still uses apps like Facebook and are more conventional. They have a longer attention span and don’t mind textual input.
Socioeconomic status: This is evident in the digital divide. Poorer families may not have had exposure to new technologies, and as a result have low technological literacy. Meanwhile, richer families have the resources to purchase new technologies, and have higher technological literacy. This may mean that richer families may find new technology easier to use. However, the converse may be true for perceived usefulness. Richer families have access to the latest technology, and therefore may be unimpressed when presented with innovation, while the same innovation may be a big improvement for the poor family with little exposure beforehand.
Compatibility and integration: It would also depend on how the technology is able to be integrated to the person’s life and other devices. For example, when I purchase a Google smartwatch, and I also own a Google phone, I find the whole system very convenient and easy to use as it is compatible. Everything syncs up beautifully and I have my health data on the Google ecosystem. However, if I purchase the smartwatch from another brand, my perceived ease of use and usefulness may drop. For example, if I purchase an Apple Watch, it may not sync up with my Google phone, and I would have to spend the effort to set things up. Therefore, compatibility and integration is an important factor as well.