I was thinking the other day about that, sort of. Apple in the early 2000s was really into things like CalDAV and WebDAV. Safari had integrated RSS reading at one point. They embraced standardization and interoperability for many things, at least where important user data was concerned. Then something happened after the iPhone took off and iCloud became a thing, and they became all about vendor lock-in. I assume it comes from being a market leader instead of only having a relatively unpopular computing platform.
there also are non-nefarious reason for dropping open standards ( obviously lock-in and profit where a big plus for them ), one would be that on your own technology you can implement, drop, and/or modify whatever functionality you want
