If you don't want Canonical's packages, you should probably just be using Debian rather than Ubuntu. It's not 2008 anymore, stock Debian is quite user-friendly.
Worth noting is that in Debian experimental coreutils defaults to coreutils-from-uutils [0]. This came as a big surprise and as far as I can tell there's been no discussion. A Canonical developer seems to have unilaterally overwritten the coreutils package without discussing with the maintainer. All the package renames that are in Ubuntu aren't in Debian so you can't switch to GNU utils either without deep trickery in a separate recovery environment.
I'm used to running experimental software but I wasn't ready for my computer to not boot one day because of uutils. The `-Z` flag for `cp` wasn't implemented in the 9 month old version shipped in Debian at that time so initramfs creation failed...
It's in experimental only, not unstable or testing. That said I'm surprised it hasn't even propmpted discussion on debian-devel (sans [0]). I would've thought that at least enough Debian developers run experimental to have noticed and raise the issue, but no. I thought about starting a thread myself but couldn't be bothered.
There aren't true 1:1 clones, but there's ripgrep (inspired by GNU grep) and fd (inspired by GNU find). Those two I like, though. I think they're thoughtfully designed and in ripgrep's case at least (I just haven't read posts/comments by fd's author), it was developed with some close study of other grep implementations. I still use GNU grep and GNU find as well, but rg and fd are often nice for me.