I can confirm the longevity part from own experience.

I bought several used Dell Wyse 5070. The 5070 was announced in May 2018 and used as thin client.
They're tiny, silent and you can fit a NVMe SSD via adapter in the WiFi card slot next to a SATA SSD. I picked the ones with Intel Celeron J4105 (Quad Core) with 1.5GHz, up to 2.5GHz burst and put 32 GB RAM in one of them.
Now I have a PVE (Proxmox Virtual Environment) running with several virtual servers, one 5070 hosts a PBS (Proxmox Backup Server) and both devices are far from their limit. In case of hardware failure I have spare 5070s.
Each 5070 cost around $65 and runs at around 8 watts at average.

It fits my needs and will continue to do so for the foreseeable future.