> Spanish is totally systematic in this sense and once you can read it, you can pronounce it.
IMHO purely phonemic orthography makes orthography unnecessary complex, as there are language features like assimilation[1] that happens naturally in spoken form but does not make sense in written form.
In contrast, morphophonemic orthography keeps systematic and consistent mapping between spoken and written form for individual morphemes, but not necessary for words, as in written form morphemes are just concatenated (to make words), while in spoken form there may be complex interactions.
It's not so strict, but we try most time to keep it consistent. For example, here in Buenos Aires we almost don't say the "d" at the end of the word, like in "ciudad" (city), in some pronunciation guides I saw it written with a tiny d.
If the variant get's too popular the two versions become the official spelling, for example "septiembre" and "setiembre" (September) are correct. I hate the second one and I never use it, but it's popular somewhere. After many years, sometime the old spelling disappears and is marked as archaic.
An orthography that surfaces (non-phonemic) assimilation would be phonetic rather than phonemic. For example, many languages assimilate "n" to "m" before "b", but the phoneme is still /n/, and native speakers are often not even aware that this assimilation occurs (which is what indicates that it's still the same phoneme).
This is true, but Spanish orthography isn't completely phonemic (and simpler for it). It is very shallow and very consistent but it doesn't spell out things like assimilation differences, people are just wrong to describe it as completely phonemic.
IMHO purely phonemic orthography makes orthography unnecessary complex, as there are language features like assimilation[1] that happens naturally in spoken form but does not make sense in written form.
In contrast, morphophonemic orthography keeps systematic and consistent mapping between spoken and written form for individual morphemes, but not necessary for words, as in written form morphemes are just concatenated (to make words), while in spoken form there may be complex interactions.
[1] https://en.wikipedia.org/wiki/Assimilation_(linguistics)