There are enough radicals that it's reasonably common you can indicate both the likely correct pronunciation and a bit of the meaning with one of them, and radicals can also be compounded/nested (e.g. combine two radicals to make a character, then that character is used as a radical in another character). It's why the standardised vocabulary test, HSK, is so important, because very often more technical or less common characters are built from more common characters that you do know. Sort of like English, where I could tell you that I majored in "lemonadology", and even though that's not a word you've ever seen you would probably have a decent idea how to pronounce it, and that it's probably got something to do with studying lemons, likely in the form of lemonade. This is informed by a cultural context where we both know and understand what "lemonade" is and means, as well as just the knowledge of the "ade" and "ology" suffixes, and the "lemon" noun. The same thing happens with Chinese characters, sort of. Those characters contain a lot of information, they are very much not just tens of thousands of letters. Also, new characters are invented occasionally by people combining previous characters and radicals, although that's less common than in English. And "word" in Chinese can encompass both many individual characters that can be considered words on their own, but also combinations of characters that form a distinct word. Like 老公 means husband, so it's a word, but if you interpreted it as two words you could read it as "old man"；no Chinese speaker would do so seriously, it's not ambiguous in its "husband" meaning, but it comes into play when wondering why 老公 is different from 丈夫，which is a different way to say husband with a different cultural context.
For reference, Chinese people think their language is very easy and that English is absurdly hard (for example, that we have an absolutely unnecessary yet mandatory number of ways to indicate tenses and plurality, and if you screw them up we think you're stupid even though there's no legitimate functional use for the differences - to say nothing of the fact that even with simple pluralisation like adding an "s", that's not one sound, that's three distinct sounds that a Chinese person would need to learn). A nationalistic Chinese on Weibo might air the opinion that the Chinese script is more optimised/easier to grasp conceptually when you aren't familiar with the concept than English, where you have to have familiarity with the suffixes and prefixes of two separate non-English languages (one of them dead!) as table stakes, plus a lot of familiarity with French. Of course, this wouldn't be correct, most people don't really understand a new word they come across in that much detail (in English or Chinese), it's just because you're not a speaker of the language and it's in a different script that it seems so hard to you. I promise you, Chinese is not objectively harder than English to learn. Chinese children have the same language development timeline as English and Arabic speakers, and Chinese scientists are very prolific and accomplished. Chinese is just quite difficult to learn for an English speaker.