A cheap used office computer with a good CPU and decent RAM can far exceed the power of a Pi. That's been my strategy. I just Frankenstein it a bit with leftover parts from my gaming computer and load it up with disks.
There's good deals on lenovo m900s or dell optiplex that are great for this. New enough to have low idle wattage and decent performance for VMs and containers, and old enough that they're cheap.
I do this. Random ebay junk is both better and cheaper than a raspberry pi. When I first started doing home server stuff, I had the option between an Athlon XP and a raspberry pi and the Athlon XP delivered better performance (I tried both).
I’ve done it a ton in the past, I’ll do it again in the future, but having a essentially plug and play tiny little box that sips juice and still does what I need while being silent… is rather nice
I bought a couple Raspis before they even came out, and they're handy for certain applications, but just can't really stand up to the task for whole home server needs.
I have a RPi1B that runs Pihole just fine, and I have a RPi4 that runs a bunch of services fine (plug in a SSD, don't use a SD card).
But if you're hoping to do a photo server or run a media centre... nah. Rpis are very power efficient, but for media you really need something that's gonna suck more power.
The Raspberry Pi: When "a computer, any computer" will do. I have so many of them in service bolted to the backs of televisions or monitors as digital signage.