is 9 mb of memory for a background image (in canvas)(exported from illustrator in psd) of main menu of your 2d game too much?
I wouldn’t say it’s a game breaker, but I am assuming you’ll have to add more textures into your game and it’s a good idea to be familiar with how to optimize texture sizes.
It’s important to set the max size of your textures to the smallest possible size without noticeably reducing the quality. Also, the filter mode should be set to bilinear in most cases unless you’re working with pixel art then use point. Also make sure your image is 256x256, 512x512,1024x1024, etc because Unity can optimize it better.