He was asking, not putting forward an argument.
Trusting a CA that uses 4 as the private key is risky. If it's a small CA that issued certs that you don't need to consume, it would be an unnecessary risk to trust it.
Trusting a CA that uses 4 as the private key is risky. If it's a small CA that issued certs that you don't need to consume, it would be an unnecessary risk to trust it.
So you'd just end up with the big players (ex. Sectigo, who cross-signed these certs btw), who would then claim too big to fail should anything actually go wrong with them (see: Comodo).