The 3B+ was probably the high of the raspberry pi. It is still pretty much unrivaled in terms of idle power consumption and energy efficiency (or at least i have not seen any other SBC that got below 0.5 Watts on idle) on the consumer market.

But i have trouble investing further into them.

1. They do not post any update guides for newer Debian releases and basically only support new deployments.
2. It looks like they are abandoning their older products. vcgencmd for example is still broken on the 3B+. Since they “fixed” it for the 4B. See https://github.com/raspberrypi/firmware/issues/1224