While supporting thousands of Apple laptop's for our organization, I have noticed that the replacement keyboards do tend to hold up much better than the original keyboard from the factory. There have been times we had to have the keyboard replaced a second time, but it is much more rare for this to occur a second time in my experience.
Besides the design/manufacturing flaw with the Butterfly keyboards, the Butterfly mechanism has very little clearance so even just a tiny spec of dirt, or a tiny crumb, or just a tiny bit of liquid can cause the butterfly mechanism to gum up and jam which may produce very similar symptoms to the actual hardware design/manufacturing flaw. I've learned how to distinguish between them from testing so many of them, but most people will never be able to tell if the issue they have is from the design/manufacturing flaw, or if it is just dirt/liquid causing the problem.
The best you can do at this point is to try cleaning the keyboard using compressed air by following the instructions in this Apple article. Make sure to hold the can of compressed air completely upright, or you may damage the laptop with cold wet propellant from the can of compressed air.
How to clean the keyboard of your MacBook or MacBook Pro - Apple Support
FYI, Apple would replace the keyboard up to two times as long as the failure occurred within four years of the purchase of the laptop.
If your laptop's battery condition is showing as "Service Recommended" (or the Apple Diagnostics reports a battery failure/issue), then you can have Apple or an Apple Authorized Service Provider replace the battery for you which is much less expensive than replacing the keyboard even though Apple will be replacing the exact same part for the battery replacement since the battery is glued to the underside of the palmrest/trackpad area. If you actually have the 2016 model, then beware it is now considered "Vintage" so repairs are only possible as long as the necessary part(s) are still available (they should be since the exact same part was used for the 2017 model which is still fully supported).
