Imagine if I have 8 plugins that I pay anywhere from $10-30 a month, per plugin. That's 8 things that can break when Shopify changes some API related things and now I have 8 different parties that I need to seek support from to get my store up and running. God forbid if the developer ceases to exist and bailed out of Shopify ecosystem. I am getting nervous just thinking about this whole "app store" model for business critical infrastructure.
May be I am not well informed in this space, but there are also services that help glue various other services such as IFTTT, and a few others that combine GSuite, Asana, Dropbox, Slack, etc... I can't remember them but I wonder what kind of nightmares I would have to rely on fragmented infrastructure that consists of chained API calls managed by independent companies. Mind you, the middle broker of API also wants the slice of the business so they're going to either charge $/month or worse - ads. Then there is the whole privacy/security aspect. Holycrap what a mess!