You misunderstood, I think... I'm saying if you know the 214 radicals and you see the character for e.g. house, you'll understand the character(s) and even sentences (sometimes).

If you know the radical 黑 and 死, then you can easily infer the meaning of 黑死病. Even though the third character is not a radical, you can spot the radical for 'sickness' there. The other component looks a lot like the radical for 'skin'. So that last character's meaning is actually something like 'skin-disease' or 'disease of the skin'. The three characters combined basically means 'black death'. As in the plague.

Maybe you can guess some hand-picked examples, but that's it. Your analysis of 病 is incorrect. It's a phono-semantic compound of 疒 (sickness) and 丙 (pronounced "bing"). From this you can deduce that 病 is pronounced similar to "bing" (or used to, in ancient Chinese) and has sickness-related meaning.

Some characters actually do combine the meanings of several radicals, for example 孝 is a child carrying an elder on their back or something; it means "filial piety" (respect for elders). But there are not that many of them, and you have to know the final meaning anyway, otherwise it's hard to guess.

At least I was right about 'sickness', which was the vital clue here.

And I can "guess" a lot more than hand-picked examples, using this method I've understood everything from store signs and logos to large parts of children's stories. Granted, I've learned a lot of characters also.

There are many recommendations to learn Chinese this way.