The phrase "and infinitely more complex" is correct and usable in written English.
It can be used to emphasize that something is not only complex but also has an endless level of complexity beyond what has been mentioned.
Example: "The universe is vast, mysterious, and infinitely more complex than we can comprehend."
Alternatives: "and far more intricate" or "and endlessly complicated".
After all, the body is the product of nature and infinitely more complex than a 777 airplane.
These days the system works roughly the same way it's just bigger, richer, and infinitely more complex.
Their work acts as re-conditioning protocol to cognition and perception so that everyday phenomena, such as wave patterns on water affected by wind, appear intensely more engrossing, supernatural and infinitely more complex than they were before.
The increasingly estimable-looking camouflage that fashion is taking on makes the process of detecting its presence and influence infinitely more complex, and makes anyone seem churlish who takes issue with it once it is detected.
The conversations with customers and prospects are infinitely more complex and important than "What color ink do you want to print" or "Are you mailing First Class or Standard?" Strategizing, goal setting, media mix and countless other aspects of marketing must all be worked into a comprehensive plan in order to achieve the desired result for each customer.
They raise questions of professionalism, command and control in an infinitely more complex and demanding media era.
(The unofficial line, involving suggestions of vested interests that hadn't been served, cops, payoffs, double-dealing and political muscle-flexing, was, like much else in Bombay, infinitely more complex and hard to fathom).
Microbial metabolism is infinitely more complex and diverse than that of their mammal hosts, and much of what we eat cannot be digested without the aid of gut microflora.
The hardware theatre is infinitely more complex and fragmented now.
American composer James Tenney was fixated on tuning systems that he felt were infinitely more complex and multi-layered than the standard equal temperament, the system through which Western orchestras and instruments are tuned.
Though she will never have another part as memorable or popular as Princess Leia, she will always be infinitely more complex and compelling off-screen than anything a scriptwriter could conceive.
