I suspect some of the 'less premium' smaller/cheaper cars got it as standard quite early on as it would have been seen as an important feature for prospective (young) purchasers.
That, plus having sourced basic infotainment systems from elsewhere (the Bosch SLDA unit in the higher-end Suzuki models is just that, basic), providing access to more clever software i.e. Apple CarPlay and Android Auto, is a workaround that also removes the need for Suzuki to develop its own complex infotainment system software in-house.
Top tier manufacturers like MB are very proud of their infotainment software, and so I guess that they only reluctantly and begrudgingly agree to drivers using Apple CarPlay or Android Auto instead of MBUX.
I think that that's also the reason why Tesla never supported Apple CarPlay and Android Auto (although they said they would have it for their 2024 cars?), in a nutshell they probably see it as an insult to their own remarkable software development capabilities. See also:
"Tesla's preference for in-house software is the most obvious reason for omitting CarPlay and Android Auto. Their own system already provides many desired features, ensuring a complete user experience. Furthermore, Tesla believes integrating these third-party systems could disrupt its already established seamless user experience. Tesla's tightly woven software features might clash with the independent functionality of CarPlay and Android Auto, potentially fracturing the holistic Tesla experience.
Adding another layer of context is Elon Musk's view of Apple as a direct competitor. Tesla positions itself not only as a carmaker but also as a tech company, placing it in direct competition with tech giants like Apple and Google. While some may find the lack of Apple CarPlay and Android Auto frustrating, it is a strategic move by Tesla to maintain its distinct identity and compete effectively in the tech industry. As such, it's highly unlikely that we'll see Apple CarPlay or Android Auto compatibility in Tesla models anytime soon."