https://arstechnica.com/gadgets/2023/06/macos-sonoma-drops-support-for-another-wide-swath-of-intel-macs/

With the introduction of the Apple Silicon Mac Pro, Apple has finally completed the Apple Silicon transition and booted all Intel Macs from its current lineup. But software support for Intel Macs isn't quite done, at least not yet. The macOS Sonoma update will still run on a couple generations of Intel Macs, but in general, if you're using anything made before 2018 or anything without an Apple T2 chip in it, you won't be able to run the new OS.