Unrestricted API keys were always secrets. They are created on a page called "Keys & Credentials". The fact that Google even allows unrestricted keys to be created has been a long standing security problem. The fact their docs encouraged it remains unforgivable.
I would like to restrict the term "Public keys" to refer to asymmetric encryption keys which can be made public without compromising security.
The only purpose of the keys Maps/Stripe encourage you to publicly put into your website is to guarantee it is talking to _your_ Google/Stripe account not someone else's. Obviously once you put them in your client they are of zero value in helping Google/Stripe identify you. The fact that Google allows you to use the same type of key they also use elsewhere to identify _you_ not _them_ was always incredibly bad design. Google already have the 'Project ID' which would have been the best thing to use.
