Some competition is OK. For example, similar programming languages (e.g. Rust and Zig) - they inspire each other, fit slightly different niches, and there's plenty of space for both.
Experimentation is OK. DNF started as a yum fork, with a different solver algorithm. IMHO yum should've just adopted the algorithm, but Fedora/CentOS ended up switching. That's mostly fine (people had to update docs, retrain their muscle memory).
The level of "competition" we see in package managers, desktop environments, initrd builders (!), resolv.conf managers (!!!), is just wasted effort. There's no "pick the winner", it's "everyone is a loser".