Yes, but we are here talking about EU days, when medical insurance for people with
pre-existing condition/s was very expensive, but accessible, available even- because EHIC covered the emergency part - private insurance covered the interim and the earliest possible safe repatriation to NHS care. Travel Insurance recovered the emergency part of cost- and this made it as cheap as possible.
Yes but, yes but, yes but..... biba every holiday you book clearly tells you to make sure that you should arrange for full travel insurance and not to solely rely on EHIC; you know this so what is the point of labouring the point? Very few countries have a free at the point of access healthcare system like the NHS, so you'd have to be completely irresponsible, or stupid, to rely on EHIC alone.