> I assume you're trying to imply that it comes from the government.

Yes, because that's how our current system works. The government prints money whenever a bank wants to lend it out, regardless of whether additional wealth was created or not.

> Fractional reserve banking started before central banks

Sure, and in those past systems, individual banks printed money to lend out, regardless of whether additional wealth was created or not. But in our current system, only the government is allowed to do that. Not that that absolves the banks--see below.

> which people would accept as payment for goods and serviced because the bank was reputable.

Yes. But what does "reputable" mean? What people thought it meant, back in the days when banking was young, was that the bank only lent out wealth that some other depositor had put in. In other words, when you took out a loan from the bank, you believed you were borrowing actual wealth that someone else had made available, and you paid an extra fee (the interest on the loan) for the use of that wealth in some (hopefully) profitable enterprise. The bank, in turn, made a profit as a middleman or broker, hooking up people who had surplus wealth to invest with people who had business enterprises that needed wealth.

But then some banks got the bright idea that they could increase their profits by printing more notes than they actually had wealth on deposit, and relying on people's belief that they were "reputable" to get those notes accepted at par--i.e., at the same rate as if they were actually backed by real wealth. If we actually described things as they were, instead of using euphemisms like "fractional reserve banking", the proper name for this would be "fraud". But it also happens to work, as long as one doesn't call it by its right name. Although it does have the downside of creating periodic financial panics, whenever people actually figure out that there isn't enough wealth on deposit at the bank to back all of the notes in circulation, and then they start rushing to the bank to redeem their notes for actual wealth before everyone else does--in other words, a bank run. One of the reasons that banks prefer to have the government do the money printing is that it eliminates this failure mode (in exchange for other worse ones)--see below.

> Since most of our money is digital nowadays, it would be even easier than in the past: the major banks could get together and just agree to tick up someone's account by X amount when another bank requests it. No government required.

They "could" do that in the sense of it being physically possible, sure. But in fact they don't, because it's illegal. Instead, they got the government to create the Federal Reserve, which does the money printing and allows the banks to maintain plausible deniability. It also has the advantage that, unlike private banks, the government can force people to accept its notes as legal tender, which eliminates the possibility of a bank run in the usual sense (though it certainly does not eliminate financial panics and boom/bust cycles, as we are now all too aware). I'm certainly not saying the banks are blameless in all this; I'm just saying that their current method of transferring wealth to their own pockets requires the government as a middleman.