This is not the same as holding hands in public which is an expression of affection”
So by all means don’t do it with your spouse. Sometimes it is also an expression of a wife needing her husband to help her walk or vice versa. I always hold onto my husband’s arm when we walk. And it is not really negiah in the halachic issur sense, when it is between husband and wife and she is not niddah. Negiah and chibah are two different concepts. True they may overlap in some areas, but they are still two separate inyanim.