You have a lot of reasons to believe you'll need the more space -- and I enumerated a few.

Ignoring those might be the venturing into the irrational range that you mentioned.

You need a place to live now. You can always sell it later - perhaps at a profit, perhaps at a loss - but a place to live optimized for your current conditions will let you save up money to buy a better place later, that will be optimized for your future conditions.

Prior to the pandemic, if you and your spouse both had jobs where you worked in company offices, then paying extra for a house that would support home offices for both of you is a huge expense. If you think every couple should do so just because they might both need to work from home some day, then you seriously overestimate how much extra money most families have available. Or underestimate how much money those extra rooms add to the cost of a house.