It certainly isnt and ít made a macbookpro a viable desktop replacement for me [using both Nvidea in bootcamp, and an AMD W5700x in mac]E-GPU supported videocards that are 2-5-10X faster than the M1 GPU, plus they supported 8-16GB of dedicated video memory. The new machines are limited to 8Gb or 16GB of total memory, so no, they didn't stop the support because the integrated GPU was better for everyone.
Egpu allows desktop performance on graphic intensive task [I am talking 100% utilisation in my pro apps].
it also took any heat out the laptop and helped it run cool.
Really though I learned my lesson in life finally in the last year. Laptop for mobile - desktop for heavy lifting. It seems Apple want us to follow that rule.
Those who think this integrated GPU will be fine for everyone, really don't know what everyone does.
But for consumer use, these machines will be great [I dont include gaming for consumer use on a mac as there are no AAA games].