Sure, it's always cheaper to use the hardware you've got than to buy something new! And you don't lose much: AV1 and VP9 compatibility the same, and probably your home doesn't use more than NVIDIA's maximum of 3 simultaneous transcodes anyway. And IIRC that's about the maximum 4k transcode throughput of a 1070 regardless.

Personally I moved from NVIDIA to quicksync exactly because I felt NVIDIA required too much babysitting. Driver compatibility, interactive mode updates, patches and patch compatibility... In comparison the intel driver felt like a cake walk. But you should definitely go with your own comfort level, especially for the price point!