Here's why:
* Newly acquired wealth: Trimalchio is a freedman, meaning he was formerly a slave, who has made a fortune through dubious means, likely through business or trade. He's constantly flaunting his wealth and wants everyone to know how much money he has.
* Lack of refinement: Trimalchio is vulgar and lacks the social graces expected of wealthy individuals. He speaks in a crude manner, shows off his wealth in an ostentatious and tasteless way, and has little understanding of true elegance or sophistication.
* Desire for social status: Despite his wealth, Trimalchio desperately wants to be accepted by the Roman elite. He throws elaborate parties and tries to impress guests with his knowledge and possessions, but his efforts are often clumsy and embarrassing.
* Crass materialism: Trimalchio places a high value on material possessions and measures success in terms of wealth. He obsessively displays his wealth, but it's clear he doesn't truly understand its meaning or how to use it effectively.
While other characters like Ascyltos and Encolpius may be considered boorish, Trimalchio is the most prominent example of a nouveau riche freedman who embodies the caricature of the newly wealthy and lacking in good taste. His character serves as a satirical commentary on the social anxieties and aspirations of the Roman world.