The main counter to this is account limits. For example we had our staging and live environments in one account. We load tested on staging (which has its own VPC) expecting it not to affect production. But because we hit account limits in the process of load testing, production Lambdas stopped responding as we exceeded the account limits.
We now have a Control Tower setup to ensure that anything we do to staging can never take down production, even if it's an account limit breach.
We now have a Control Tower setup to ensure that anything we do to staging can never take down production, even if it's an account limit breach.