Up until the very latest generation of Macs, Apple was behind every other manufacturer when it came to 8th gen Intel chips.
Dave2D has several videos before the most recent line-up telling people not to buy Apple laptops unless they needed specific Apple software as all the high end Dell, HP, Asus and MSI offerings had better hardware for more reasonable prices.
Even now, you can find a lot of gaming and content creator laptops that are just as good, and sometimes even cheaper than the current Apple laptops. For an i9, it doesn't matter who you pick, they're all throttled.
If you're getting an i9, you should really get a gaming laptop instead. There are several that are built with very good thermals and won't throttle (although you'll have to dig through Linus/Dave2D reviews to find the specific models) and that are great for video editing and rendering as well.