macOS Sonoma was just announced last month at WWDC and there are some enticing macOS 14 features that may convince you to update, but not everyone has that option. MacBooks made before 2018 didn't make the cut for support this year and it's possible the last of the Intel-based MacBooks will join them next year with the release of macOS 15.
That speculation stems from extensive research done by ArsTechnica surrounding macOS support going all the way back to 1998, which lays out the case for Apple potentially hitting the kill switch early on Intel Macs due in large part to the Apple Silicon transition that kicked off in 2020.
