Whether that's your "whole stack" or something "ad-hoc" is a totally arbitrary distinction. Your "whole stack" will almost certainly involve external concerns, and your "ad-hoc" concerns will almost certainly grow in complexity until they converge on the same spot.
AppEngine is also running containers via gvisor.
The distinction is being driven by PMs and marketers but not by the needs of customers. What end-users need is one well-supported tool, not 8 separate tools with uncertainty about which one will receive future support and matrices and flowcharts to decide between them.
