I don’t mean them specifically, but that to me managing access to such a CA cert’s keys is security nightmare, because if I somehow get an infection, and it finds the cert file and the private key, it’ll be much easier for it to make itself more persistent than I want it.

If you can’t resist installing random shit on your CA server then sure. No attacker will really try to compromise a home CA so you really only have to worry about viruses which should be kept extremely far from the CA anyways. And obviously follow all other security precautions like good passwords or even passwordless with certificate login (remember that you have a CA server so you can easily issue authentication certificates and enroll them on a smart card or Yubikey)

The private key should also be in TPM (or a HSM like we do at work, but that’s a bit extreme for home use) and be non-exportable. Managing access to the private key isn’t really that hard, it should just never ever leave the CA server and you are pretty much good to go.

You can also do a two tier PKI with an offline CA and an issuing CA like I’m planning to do for an AD DS, AD CS, AD FS lab.

Personally I think wildcard certificates sound like a bigger security problem than a CA since that certificates will likely be placed on a lot of servers and if just a single one gets compromised the attacker can impersonate whatever subdomain they feel like. With a CA server you could issue individual certificates to each server/service

Private CA servers are very common and is actually a security positive. I’m not saying that everyone needs one at home, but you shouldn’t be afraid to setup one if you want too.