How to reduce image size without losing quality and without increasing image size?

Question

Adobe Photoshop

I have a 1850x4670 image weighing 2.03MB, I need it to weigh less, the dimensions can be reduced by 30%, I throw it into Photoshop, create a new 1259x3269 dock, copy this image there and fit it with a transform to fit the borders, as a result I got a 1259x3269 image and weighing 3.6Mb ....
How would I think that the smaller the size of the picture, then it will weigh less, but it turned out almost 2 times more ...
Tell me how to reduce it so that the weight decreases with the size?

Answer 1

Via https://squoosh.app/