I also put everything in one repo nowadays, no matter the usage, the language etc. All is synced, and all is accessible by my LLM. There are a lot of tools to manage monorepos, and frankly most of the time you don't even need them.
Not a big deal if you're basically the only developer and handroll the process - but poly repositories make release and dependency management a lot more straightforward to wrangle
It is unlikely GB/TB is ever a measure, though if your repo is that big and some people only need a subset of the repo it would be.