It's funny, I started with rPis for the same reason, but I'm about to replace them. I bought 20 rPi 4Bs for my homelab, and I just couldn't get them to do what I needed. I was looking to run a home k8s cluster and the Pis were just not suited to it at all (don't use sd storage for k8s 'cause it'll burn out the card w/writes, booting off usb was unstable even with powered usb hubs, netboot turned into an enormous pain in the neck).
If you have another machine with a SSD or at least a fast-ish HDD and want to give it another go, you could try running k3s with an external datastore (e.g. postgres).
That's the setup I've been using on 3 x rPi since 2021 and I'm super happy with it as I can host all my own personal projects, some OSS ones (changedetection, n8n, etc), even longhorn for distributed storage and still have capacity left -- and this with just microSDs (to be fair, A1s, but still).
Yes, I moved to 1L PCs for lab work.
https://news.ycombinator.com/item?id=40697831