Sure it would, in time. The barrels, slides, frames, triggers parts, etc. that are now available for the Glock are either OEM or upgrades to OEM -- in other words they're still pricey. If interest grew like it did for the AR15, I'm sure a $199.99 or less Klock 17 would be possible with very decent margins.
I've been entertaining this idea, as I do build a lot of custom firearms, but this $199.99 price point is nothing short of ridiculous.
Why do you believe that would be true? Because all of the parts you mention are currently available, and in a dozen Glocks I have built, I've spent more than TRIPLE what you are stating.
Why do you think AR-15 pricing supports a Klock 17 price point less than 40% of the retail price of a factory model? For AR-15 carbines, the LOWEST build price a guy can get is somewhere $300-350, whereas you can hit sales for $500 on Factory carbines just as easily as finding those sale prices on parts. Most guys struggle to build one under $400. So you're talking about a $500 factory AR for $350-400, but then turning around and saying you can build a $500 factory Glock clone for $200? Forgive me if I don't understand your reasoning for laying out different numbers, and calling them the same.
Could you please start from our current reality of $150+ barrels, $200+ slides, $50-100 LPK's, and $70-100+ 80% frame kits, $100 slide completion kits and walk through how each of these components will become so much cheaper just through open source production? The list I've provided above makes a basic "Klock 17" with readily available aftermarket and OEM parts for $570, please do explain how you will get us down to $200 total cost?
Reminding here, the cheapest of the cheap open source 1911 barrels are $50-75, which gives you a head start with a $75-100 knock off on what I have listed above... But also reminding, the cheapest of the cheap AR-15 LPK's which include the FCG are $40+, so you likely have no room at all to come down on that bit of kit. You've repeatedly dropped out $50 as the goal for your frame cost, which is only $20 reduced from the current price on Polymer 80 kits. So that's a head start for you - $120 off of the list above is $450. I could be convinced a slide completion kit could be bought for less than $100, so let's all pretend for a second and say it would be priced comparably to an AR bolt rehab kit, for $50. That's another $50 off. So now we're at $200 before you have bought a slide or sights, which puts us right at $400. So here's where things get really silly, let's pretend in the future you can get a Klock slide made at Sarco prices (which doesn't exist today for Glock slides), so you're talking $100 instead of $200, that's still $300 into an open source Klock 17, with a home-milled lower and a crappy Brazilian made slide. And that's a long damned road to bring those prices down another $100 to meet that $199 price point - and I sure don't see any margin for retail dealers after cutting all of those SALE prices again in half.
$570+ is our reality today, and $300+ is pure speculation a guy can cut the cost of almost all of the major components IN HALF, or even cut by 75% in the case of the barrel. You don't see $100 slides at all, and you don't see $50 pistol barrels very often.
I've been building and rebuilding guns for far too long to believe an open source "Klock 17" could be built for $200, or even for $300! It's just not going to happen. I've built on Polymer80 frames and the $600 mark for a base model is real. Granted, nobody builds a base model, as the point of building a custom is to end up with something custom, not end up with the same generic Glock everyone else has, for the same price PLUS more work and no warranty.
So what is the firearms production world missing which you are not? How do you propose to cut another $100 off of that absolutely ridiculous thought experiment I went through above?