Ahhh - but remember at various points already we've had "I've played every SQ42 mission", "the core of the game is done at this point", "we have the entire first chapter playable and ready to show to backers now, but we've decided to delay a couple of weeks as Genuine Roberts wasn't perfectly happy with one or two animations", "we have fantastic completed segments the crew can't wait to show off, but can't because spoilers" and a whole bucket of other such crackers
While these are fantastic counter-points, the scenario that I've seen most supported (i.e. the most upvoted guesstimates) is that Sq42 was rebooted in or around 2016 - as int the the one in development now is a different one to the previous, because of scope changes resulting from lots-of-cash-received-from-backers.
Sq42 has not taken a long time to create, because technically
this game only started development a couple of years ago.
Now, if I remember correctly both Star Citizen & Squadron 42 changed engines from CryEngine to Lumberyard during 2016 too, but I'm neither a coder nor a lawyer
What this all means in the grand scheme of things I do not know.
But I do like annoying the shills non-the-less
