Not many people know that Cuda stands for Compute Unified Device Architecture.
The unified being the key idea here. All NVIDIA GPUs support Cuda since the G80/G84/G86 generation which arrived at the end of 2006, beginning of 2007.
It’s true of course that the older GPUs don’t support newer versions of CUDA, but the idea that CUDA is unified has been central to the project since the beginning. It also has cost a lot of money and effort for NVIDIA to put CUDA support in every GPU, even when it wasn’t extensively used. Took about 10 years of investment before it really started to pay off.
CUDA will run at least run on anything that says “Nvidia” on it from the past five years or longer.