For example, Apple introduced predictive typing with the QuickType keyboard over 6 years ago, but it still only supports 18 languages. This means that users speaking some languages, including Polish with over 40 million speakers and smaller languages with many iPhone users like Norwegian, might still not be able to use predictive typing. The QuickPath keyboard only supports 7 languages and no new languages have been added since Apple added the feature a year ago. Similarly, iOS only has a built-in dictionary with definitions for 18 languages and the thesaurus is only available for English (United Kingdom and United States).
Scribble on iPadOS is only available in 3 languages even though Apple has predictive typing, contextual suggestions, dictionaries, autocorrection and spell check for many more languages. The extra work would mostly consist of adding support for characters that are specific to that language (for example many languages that use the Latin alphabet have most of their characters in common with English that is supported).
Craig Federighi has even said that Apple has gathered handwriting data from people all over the world. The situation is even worse for Apple Watch with only 7 languages, which is very few when you consider that Scribble has been available on watchOS for over 4 years. If your language isn't supported and you want to respond to a text directly on your watch without picking up your iPhone, you're forced to use a suggested reply or use dictation, which isn't very practical if you want to reply to a very personal message in public for example.
The languages offline dictation is offered in are also very few. Siri also lacks support for many languages like Czech, Polish, Greece and Vietnamese. Many languages that actually support Siri lack many features that Siri has for English (United States), including translation which is only available in 11 languages after 3 years. Voicemail transcription (although it is in beta) is also only available in English 4 years after the feature debuted. HomePod and HomePod mini are also only available in a few select countries. Many countries have support for Siri in the main language on iOS, but HomePod is still not sold in these countries.
The Maps app is also very limited in terms of functionality in many countries. Major countries like Italy and Spain don't have support for lane guidance. Speed limits are only available in 6 countries and for speed cameras it's even worse, 3 countries. You can't blame this on licensing issues since many other countries have this information and could get those features if Apple was willing to pay up to license information from existing providers (which they did in the United States for the speed limits before Apple released it's own improved map). Features like Look Around and cycling directions are even worse, they are only available in a few major cities in less than a handful of countries. Transit directions are still not present in major markets including India where competitors have offered similar functionality for years. The same can be said for Flyover.
Don't get me wrong, I want Apple to spend necessary time and attention to get the details right for these features (and better than their competitors) in all the countries and languages that they decide to support, but having to wait over 6 years for predictive typing is inexcusable. Either Apple doesn't have enough staff working on these things or the company doesn't want to put money into it and focuses on more English only, United States only or only these handful of countries/languages features instead.