Lantronix has a product called Spider, which (several years ago when I used one) works wonders. To the host side it looks like a standard monitor, keyboard, mouse and usb. I’m not quite sure if they still actively develop that, but at least the product page is still available. It’s not cheap, so it might not be what you’re looking for, but I was impressed on what it can do (since the company I worked back then too care of the invoice). It can’t do power cycle or hit reset button, but beyond that it was pretty close to IPMI and other remote server management solutions.

With my own wallet I’d look for piKVM, but it’s not really cheap either and I don’t have any personal experience with it. For power cycle there’s a ton of companies who manufacure wall-warts which you can control over wifi, APC and other big players included, and for home gamers nodeMCU and shelly are solid options if you’re familiar with electronics, but they can’t do KVM over IP, so it might require using different products to remotely accessing the host and for power management.