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.
It makes releasing software a lot more complicated.
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
Most of the time your repo is so small that you won't run into the problems of a large repo and so you don't need those tools. Don't confuse that for monorepos have no problems when they get large.