quite a bit. most of my space is taken up by a full-res photograph for my first blog post and the Lainchan webring (which is decentralized; you host all the images and links urself).
i generally try to keep pages under 300kb by using low resolution and bit-depth pngs or webps at a low quality setting (and i might start using avif) or jpegs encoded using jpegli, jpeg-xl's efficient jpeg encoder.
at the end of the day, it's not the size of your site that matters, it's how well you're using that space that does. still, it's best to try to keep your pages lean. it helps with accessibility, website management and archival.
note: the outlined area in windirstat is just for the lainchan webring lol