How's that less convenient: You take the scales, take a bowl, hit tare, put stuff in, hit tare, rinse and repeat. Also just for the record milk and cream can be assumed to have the same density of water in the home kitchen, 1g/ml, oils get as low as 0.8g/ml which may or may not make a difference. Usually there's plenty of tolerance.

Where things get awkward with common kitchen scales is spices and stuff in case you want repeatability with small batch sizes. OTOH milligram scales aren't expensive, just don't expect to use them to weigh out a whole bread they take like 100g or so max.