That is really quite simple.
1. Most of your quotes are long after his death even up to 100 years later.
2. The may have been a person named jesus who was even a "preacher" and was executed for blasphemy, where stories about him have been enhanced to myth status or simply made up for the sake of good showmanship and conning a few more shekels out of foolish believers, but was does that prove?
Absolutely NOTHING.
Does it prove he was the son of god, NO
Does it prove he was from a virgin birth, NO
Does it prove he performed miracles, NO, it actually goes the other way and tends to prove he didn't perform any miracles at all
Does it prove he rose from the dead, ABSOLUTELY NOT, even the bible can't get the fairy tale consistent on this one.
Does it prove that Billions of people have been conned by the greatest ever con job, YES.
Does your reference to Alexander and Napoleon, prove you are clutching for any evidence no matter how irrelevant to support your position. YES
The real question is not whether a person named jesus existed (I am sure there were thousands of them as well as marys, davids and any other name common in those times), but are the fairy tales built up a hundred years after his death true, and the answer to that is there is ZERO evidence of this
When you read about World War I of 1914-18 and its deadly effects in history books, do you ever say that what was written down by historians is fake ? When you read about the Spanish Influenza of 1918-20 in history books, do you ever think that this is just nonsense ? When you read about the Great Depression, do you ever say that this is just gibberish because you did not experience or see the event for yourselves ?
All three world changing situations happened long before either you or I were born (unless you are at least 90 years old). Yet, we never doubt their authenticity when we examine them from qualified historians accounts or even from, say our grandfather who may have lived through those times.
You mentioned David in your post, as perhaps another person conjured up, though spoken of some 1,000 times in the Bible. Before 1993, there was no proof outside the Bible to support the historicity of David, the brave young shepherd who later became king of Israel. That year, however, archaeologists uncovered in northern Israel a basalt stone dated to the ninth century B.C.E., that experts say bears the words “House of David” and “king of Israel.”
An archaeological team headed by Professor Avraham Biran, uncovered a basalt stone (also called the Tel Dan stela) outside the outer gate of ancient Dan (Tel Dan) near the border of modern day Lebanon. It referred to the ' House of David ' (referred to in the Bible 26 times) and to the ' King of Israel '. This stone is dated to ninth century B.C.E., a little over 100 years after the death of David, or almost 3,000 years ago.
Another stone, the Mesha stela, an ancient stone slab that was also called the Moabite stone which was found at Dibon [modern day Dhiban in Jordan] about 12 miles northeast of the Dead sea and is assigned to Moabite king Mesha as his account of breaking Israel's domination over Moab in which he says lasted forty years and is recorded at 2 Kings 3 in the Bible, giving the credit to his god Chemosh, was discovered in 1868, and was also found to contain the expression ' House of David ' by Professor Andre' Lamaire, and is also dated to the ninth century B.C.E. and is of the same material as the Tel Dan stela and is written in almost identical Semitic script.
Bible critics questioned the existence of Pontius Pilate (governor of Judea from 26-36 C.E.), the Roman governor who handed Jesus over to be executed. (Matthew 27:1-26) Evidence that Pilate was once ruler of Judea is etched on a stone discovered in 1961 at the Mediterranean seaport city of Caesarea, and is now located in the Israel Museum, Jerusalem.
Another example that was seen as just a "fib" was that of Assyrian king Sargon. The Bible mentions him only once at Isaiah 20:1. Until 1843, Bible critics said that he was just a "made up" person. But in that year, near Khorsabad, on a northern tributary of the Tigris River, the palace of Assyrian King Sargon II, covering some 10 hectare or 25 acres, was discovered, and subsequent archaeological work there brought this king out of secular obscurity to a position of historical prominence. Two lamassu or protective deities from Sargon's palace at Dur-Shurrakin is exhibited at the French Louvre Museum.
So, just because you discount the authenticity of several first century historians' account about Jesus, does not change the facts. Many are like what is stated at Proverbs 18: "A stupid person takes no pleasure in understanding (doing no in-depth research nor using sound logic); He would rather disclose what is in his heart (or give his personal opinion)".(Prov 18:2)