CUDA does involve a massive investment for Nvidia. It's not that it's impossible to replicate the functionality. But once a company has replicated that functionality, that company basically is going to be selling at competitive prices, which isn't a formula for high profits.
Notably, AMD funded a CUDA clone, ZLUDA, and then quashed it[1]. Comments at the time here involved a lot of "they would always be playing catch up".
I think the mentality of chip makers generally is that they'd rather control a small slice of a market than fight competitively for a large slice. It makes sense in that they invest years in advance and expect those investments to pay high profits.
Notably, AMD funded a CUDA clone, ZLUDA, and then quashed it[1]. Comments at the time here involved a lot of "they would always be playing catch up".
I think the mentality of chip makers generally is that they'd rather control a small slice of a market than fight competitively for a large slice. It makes sense in that they invest years in advance and expect those investments to pay high profits.
[1] https://www.tomshardware.com/pc-components/gpus/amd-asks-dev...