I was basically going to quote your whole statement here and then point to the more than 19 US states that have had Water Treatment plants forced to disconnect much of their Operational Technology systems.
And those disconnects would be that effective gatekeeper. Maybe overkill, but "air gapping" is a often a reasonable mitigation.
And those disconnects would be that effective gatekeeper. Maybe overkill, but "air gapping" is a often a reasonable mitigation.