Well…firstly, you can never have enough dogs, obviously….in my opinion.
But on a more serious note; it depends, of course, but usually it actually won’t help and here are a couple of things to consider:
Your dog’s anxiety comes from being separated from you, the human, not just from being home alone. So while another dog might make your dog less lonely, it’s not likely to cure your dog’s anxiety when you’re away.
Also your current dog’s anxiety when you are not around may rub off on your second dog and then you have a double-trouble kind of situation.
So, I’m definitely all for getting a second, third, fourth dog, but do it for the right reasons, prepare yourself accordingly and enjoy your furry family.