[snidely]

I am in U.S. and have had no need for intl. SIM card since my long time carrier (T-Mobile) has included intl. roaming for 3-4 years to a vast majority of countries. Have made use of this feature in 13 or 14 countries.
(When in Myanmar (fka Burma) bought cheap local data card, put it in spare phone, and tethered our other two phones to it. TM has had wifi calling "built-in" for 10+ years. And Burma has very little land based wifi.)

I gather Europeans can now roam all over the EU "like at home". Do any carriers offer roaming to other countries?
Do Europeans still pay Long Distance charges within their own countries or to other countries? TM users can call/roam in Canada and Mexico like being at home.
Just over 50% of Americans are "cell phone only". No landline. Our 45 unit bldg. in Oakland, Ca. has only 2 landline users. (Most occupants are under 35.)

Question - Is the need for an "International SIM" no longer needed?

It sure is convenient to step off a plane in Zurich or Hong Kong and start making/receiving calls as though you just traveled from SFO to MIAmi. AND using Google Maps.