Ferguson
It is indeed not easy for children to assimilate ALL the rules, exceptions, variations and 'whatever' that are needed to reliably learn to read and spell English.
That's why children take an average of 3 years to become modestly fluent readers and at least 10 years to approach basic spelling proficiency.
Mrz
Most of the 1 million words in the OED nobody knows or uses. Many of them are not even English. When i tried to compile a basic list (e.g. including 'work', but not derivatives like 'working, workings' as well) that an average 16-yr-old can be expected to have come across, i could not find more than 7,000. - So in that sense there is much less to learn than u claim.
But English uses 205 different spellings for its 44 sounds (not 176), and even if a child can give u all the different ways a sound is spelt (e.g. the 12 for /ee/: ee, ea, e-e, e, i-e, ei, ie, eo, i, ey, is, ay - see, tea, eve, me, machine, weird, thief, people, ski, key, debris, quay), they still have to learn which one applies to each of the 452 common words with that sound. Nor will they know how pronounce the ones with variable sounds (treat, great, threat; people, leopard, leotard...the, me...they, key ...) until they have seen those words a few times.
After a bit of basic phonics, children really learn to read and write simply with lots of word by word practice, going over them again and again. As u say,
the more times they read and write the correct version then the process will become automatic.