The positive is that it's great to have the option to work from home.

The negative is that once this becomes the norm, you will be competing with people from potentially anywhere in the US (and maybe other countries as well) and wages will most likely decline.

Why would an employer pay you $250K+ in California when they can find an engineer for half the cost in another state? Most wages in Canada for software engineers are absurdly low in major cities like Toronto.