[willis936]

MEMS are made on a different process than other silicon devices, which slightly increases their cost. They also need to have hermetically sealed packaging, same as quartz. Together there is little fundamental savings to be had with MEMS, but they do offer a higher ceiling on performance. I don't see crystals going away anytime soon.

Also, if you get a MEMS in a small epoxy / CSP package be weary of gases that permeate the packaging material, such as helium.

https://hackaday.com/2018/10/31/helium-can-stop-your-iphone-...