You don't need to memorize 3000 characters, you only need to memorize 100 radicals and 200 special characters because 90% of Chinese characters are phonosemantic (形声字). That is, they contain the pronunciation within them.
Don't know how to write "arachnid" (蜘蛛）？ Easily described as 虫 radical to designate as a bug, plus 知 for pronunciation, 虫 radical for bug, plus 朱 for pronunciation.
The real advantage of Chinese and to a degree, Japanese, is that once you know the characters you no longer need to memorize any new vocabulary. Without it being explained to someone there is almost no way anyone can know what "diabetes" or "pediatric" means, they just have to memorize it. But 糖尿病 and 小儿科 are understandable to a 2nd grader. The toughest terms in English are described using very simple language which itself derives from radicals.
American students spent literal years building up their vocabulary even up to university, and vocabulary is tested extensively in SAT, GRE, etc. Meanwhile Chinese students are pretty much done with learning new vocabulary in middle school, and move on to more and more complex reading comprehension, learning how to write professionally, etc.
English is also not actually phonetic. Easy example: c in cat, c in celebrity, s in serial. No way to understand this except by memorizing.
Extreme example: Fish? No, ghit. Gh as in cough, I as in it, but t as in information. Why can't I write it that way despite precedent for all those sounds being spelled in that way? Don't know, memorize it.
