Well, yes. That's because it's a low-power low-cost device. It's not designed for video transcoding which is a relatively specialised use case FFS...
It's like you're trying to compare a hammer to a screwdriver when all you want to do is put screws in things - a hammer's the wrong tool for the job. A hammer's still a really useful tool to have though...
I've got a 3B, 4, and 5 in a rack in my loft, the 4 and 5 with cheap SSDs instead of SD cards. I've got a Zero W acting as a Bluetooth proxy downstairs.
Total cost significantly less (like, less than 1/3rd) than a Mac Mini capable of doing the same thing.
3B runs my ADS-B receiver and feeder (docker on raspbian)
4 runs HomeAssistant and NGINX very capably (docker on raspbian)
5 runs OpenWRT (bare metal) and acts as the router for my entire network, including PPPoE termination, firewall, NAT, etc, etc. Best router I've ever had, by a long, long way.