My main infrastructure is very simple and only consists of 4 devices.
This is my main router, which handles my gigabit fiber. It has Wifi 6 with support for 160MHz channel width on 5GHz. I utilize that to have gigabit+ speeds on wifi.
Gigabyte Brix J4105
I use this very low power machine with 16GB to run unRAID, Home Assistant and a dozen or so Docker services. It is also packed with 2 1TB SSDs for backups and data storage.
This QNAP NAS that I bought very cheap on iBood and filled it with 8GB of RAM. This device only has a meager Intel J1800, but that does the job. It is also a bit of a weird device as it houses 3 3.5" drive bays and 2 NVMe slots. In addition I also use USB storage. Currently it has over 30TB of internal storage and about 7TB of external storage. My NAS also runs Docker (Container Station) for a dozen or so Docker containers.
Raspberry Pi 3B+
I still use my old Home Assistant, a Raspberry Pi 3B+, for my water heater temperature probe.