I'm a big fan of Kubernetes, and for larger projects the flexibility and power it brings is unrivalled. But for smaller projects, assuming equal levels of competence, delivery teams using managed Kubernetes are almost universally later and have more issues than teams that use simpler solutions. Container-as-a-service solutions like GCP CloudRun or AWS FarGate help somewhat, but are not cheap for a given amount of compute time.
Terraform (or IaC in general) absolutely has a place, because even if you use Kubernetes, most projects have more infrastructure to manage than just the cluster - at the very least, lemmy.world has a CloudFlare proxy to manage - and clicking buttons in a management portal is not a repeatable way of deploying that, or deploying the Kubernetes clusters themselves.
Ansible also has a place, particularly if you're deploying onto bare metal. I wouldn't use it for new deployments unless I had bare metal to configure and maintain, but lemmy.world is deployed onto a bare metal server as I understand it. Plus, the most effective tooling is generally the one your team understands.
Do we have to bring this up again? It's just boring.
systemd is here and it isn't going anywhere soon. It's an improvement over SysV, but the core init system is arguably less well-designed than some of the other options that were on the table 10 years ago when its adoption started. The systemd userspace ecosystem has significantly stifled development of alternatives that provide equivalent functionality, which has led to less experimentation and innovation in those areas. In many cases those systemd add-on services provide less functionality than what they have replaced, but are adopted simply because they are part of the systemd ecosystem. The core unit file format is verbose and somewhat awkward, and the *ctl utilities are messy and sometimes unfriendly.
Like most Red Hat-originated software written in the last 15 years, it valiantly attempts to solve real problems with Linux, and mostly achieves that, but there are enough corner cases and short-sighted design decisions that it ends up being mediocre and somewhat annoying.
Personally I hope that someone comes along and takes the lessons learned and rewrites it, much like Pulseaudio has been replaced by Pipewire. Perhaps if someone decides it needs rewriting in Rust?