I am not aware of many devices that use swappable 18650's either. Off the top of my head the only ones i'm aware of are vape devices.
I refuse to buy cordless powertools. I know it's not exactly the same as built-in batteries, but In their short existence, I have already seen proprietary rechargeable batteries become discontinued (My mom wanted to get an extra battery for a handheld vacuum, couldn't find the battery by itself, so bought what she thought was the same model; nope, they changed the battery design, even though the rest of the new vacuum was the same as the old one)
Mr. Submarine i'm assuming.
In a past life I watched people do this with lumber. A con as old as big box stores return desks.
The passing resemblance to cointelpro ( https://en.wikipedia.org/wiki/COINTELPRO ) had me suspicious and it still didn't click for me until then either.