I don’t use gmap for navigation but to check locations. I had to get some cash so looked up atm and found few nearby. When I went there it was just apartments so looked up another one which turned out to just homes and small shops. Ended up getting off and asked someone working in the shop for directions and got everything I could have wanted.
Not an expert but it depends on transcoding settings. Some GPU support encoding formats like av1 while others might not so the processor would have to do that work, hence the heavy usage you have noticed. If you need to use transcoding then check what your GPU supports for encoding but transcoding in general is not preferred if you can avoid it.