Unable to upgrade to Monterey?

This question is about my 2017 MacBook Pro 13 with a 13 inch screen. I'm currently still on MacOS High Sierra, but wanted to upgrade, pretty much purely for the screen time feature which I've gathered is only available post-Catatlina (Catalina isn't coming up on the App Store so I can't seem to try that, may be for an obvious reason, haven't looked into it too much). Originally it told me I couldn't because there wasn't enough free space on my Macintosh HD, which made me weary of upgrading at all as I want some wiggle room of storage. But the screen time feature would be beneficial to me, so I deleted some things and then it started to say that I couldn't download it onto Macintosh HD, with nothing about storage issues. After some digging I tried just restarting it. But this time it once again gave me notice that didn't have enough storage, except this time the storage I needed to make up had gone up from about 3.2GB to about 4.39GB. This makes no sense, I've deleted several apps and hundreds of documents, as well as unloading some to iCloud but somehow have less storage. What would you recommend? In dummy terms please. I've attached a few screenshots in case its helpful. Cheers