all good if you know how to put It all together correctly.
However I agree with you, for certain tasks it is better to have a separate box [which I have for rendering - both CPU and GPU so is a bit of a beast.....].
When I did any rendering on my iMac previously the fans went berserk Plus the GPU was average [like the 5700 Is now].
No one computer does it all unfortunately and is something I have come to realise.
Imac = great all round computer [but isn’t portable and struggles when pushed]
Macbookpro = great reasonable powered portable [but is underpowered and has bad cooling]
Mac Pro = $$$$$
Macbook air = great portability [slow]
Ipad pro = super fast and portable [no macos]
The list goes on. I can actually justify a Hardcore PC, iMac, MacBook Pro, air and iPads plus phone. They all do something better than the other.
its all fun