Like many others, grocery delivery. I normally shop by bike, but DW forced me into Instacart delivery. It's probably adding 20-25% to our food cost with the layers of fees, as I tip more than the default.
Also upped our music subscription from the one-device 'Alexa' unlimited to full-family unlimited to help us deal with WFH while kids are are also bouncing around the house in home school.
The extra costs are certainly more than compensated by the lack of childcare costs, DW no longer going out to lunch 50-60% of the time, near-zero car use, and - for now - no trip/vacation expenses. I'm taking the savings and promptly letting it disappear in stock market declines. Also refinancing the mortgage, which will help me lose even more money in the stock market.
(I'm not actually begrudging the stock market declines; they are what they are and I'm sticking to the plan)