Some more:
In ancient Greek, words were constrained to end in a vowel, /n/ or /s/.
The Phoenecian letter names did not fit that pattern, so they were adapted to end in vowels.
Of the available vowels, nouns most frequently ended in alpha (neuters or feminines) or eta (feminines). Omega, iota and upsilon were rare noun endings; omicron was not a noun ending in ancient Greek; epsilon was restricted to the dual third conjugation. So distributionally, alpha was the easiest vowel to pick. Bisyllabic Phoenecian letter names, and letters ending in stops (t, p, k, d) all end up ending in alpha. Monosyllabic letter names alternate between iota, upsilon, and -au (which is not actually a normal Greek word ending, but is at least consistent with the rest of Greek phonotactics.)
The actual alphabetic letters are indeclinable foreign words, so this is only an analogy: the alphabet letters are neuters, but don’t decline like neuters. If you google σίγματα, which would be the expected plural of σίγμα, you’ll find Modern Greek usages—and Photius saying that the plural of σίγμα is not σίγματα.
There’s also a hint from Indo-European that Greek alpha corresponded to schwa as a “default” vowel — it corresponds to the Indo-European zero-grade (absence of a vowel).
And very significantly, alphabets are recited in order, so there’s very very strong pressure for letters to sound similar. We know that people were copying out alphabets (abecedaries) for generations, getting the hang of the new invention. So once one or two letters fitting a pattern ended in alpha, all the other letters fitting the pattern did as well.
The exceptions were the monosyllabic letters, which stayed as they were, without adding an alpha: ei (epsilon is mediaeval), ou (omicron is mediaeval), u (upsilon is mediaeval), wau (digamma is later), tau, rho, pi, mu, nu, xi. The later additions stuck with the pattern of pi: phi (a counterpart of pi), chi, psi (rhyming with phi) — and ὦ (o) for omega, matching ou for omicron.
So, referencing https://en.wikipedia.org/wiki/Ph…
ʾālep: alpha
bēt: beta
gīml: gamma
dālet: delta
çādē: zeta
ḥēt: heta
ṭēt: theta
yōd: iota
kāp: kappa
lāmed: lamda (later lambda)
qōp: koppa
ṣāmek: sigma
While there are 105 million words in the TLG, most of them are Byzantine. I did a count of the words in the corpus in Lerna VIc: A correction of word form counts in 2009; because there is not massive growth in the number of known ancient texts, the counts still apply.
If we define ancient Greece as up to the fourth century AD, and we exclude Christian works and technical works (so just literature, as opposed to writing), it’s 16 million words. If a novel is around 100,000 words, that corresponds to 160 books; so yes, someone could potentially read it. If we cut it down to strictly Ancient times (down to the fourth century BC), it’s 5 million words.
By way of comparison, the complete Loeb Classical Library (which includes all the important classical texts) has 337 volumes for Ancient Greek — and those aren’t 100,000 word-long door-stoppers.
How much has been discovered in recent years? Whatever we find in papyri, which has meant a few complete texts — notably Menander, and a trickle of new fragments like from Sappho (two in a decade). The occasional texts retrieved from manuscripts through improved technology, such as the Archimedes palimpsest. But it’s a trickle nowadays, and I would not expect it to ever become more than a trickle.