On a RPi 3 mod B? Not really. Load spikes have already been mentioned and especially Home Assistant is prone to them, PiHole can be, but it can be avoided (you still wouldn’t want it to update its blocking lists while you print something as it causes load spikes).

IF you do it you need to configure it in a way that the Octopi is getting priority over everything else - which is possible with a lot of tinkering or using a VM layer like Proxmox - which is adding to the overhead again, though. This will push the 3B to its limits even more.

Personally I would advise against it heavily. If you already have a 3B, use it for the 3D Printer and buy another device for everything else (not necessarily a Pi, Arm has it’s downsides - there are a lot of energy efficient x64 solutions out there these days.) And then slap Proxmox on it,run HAOS, Pihole and whatever comes your way in the future on it. (Paperless and Frigate/agentNVR seem to come along the way naturally.