There's one big catch with multi-region eSIMs, although in fairness it's a catch for many non-multi-region eSIMs as well too!

Roaming traffic is almost always backhauled to the country that the SIM you're using is from. So say you had a US T-Mobile account, and you were travelling in Asia, then all of the traffic would first route back to the US, then out to the internet. This adds latency, and can slow things down - although if the services you're accessing are in the US then it doesn't really change much.

Travel eSIM are often roaming SIMs as well, but they are also sometimes local. So for example, I've used 2 different travel eSIMs in Israel over the past few months. One was from a provider that was apparently based in the US, so all traffic was backhauled to the US. The second was a local provider, so traffic routed directly to Israel.

Multi-region eSIMs are always going to be roaming - at least in some countries. If your SIM happens to be from a provider in the US, then when you're in Europe all of your traffic will be backhauled to the US. If it's a Europe provider, your US traffic will be backhauled to Europe. If it happens to be an Asian provider (eg, 3 Hong Kong who are a common travel eSIM provider), both will be backhauled to Asia!

As I said, this backhauling can happen for any eSIM (unless you know it's from a local telco), but the odds of it happening are greater for the "worldwide" or "multi-region" packages. Of course, depending on what you're doing, you may not care. If you're just using Google Maps, email and some web pages, both will work equally fine. If you're trying to route phone calls over it, you might care a little more about the latency of the call literally being routed around the world.

The biggest issue with companies like Airalo is that they generally don't tell you what country the eSIM you're buying is from, and thus which country your data will be backhauled to. Sometimes it's obvious (eg, their Thailand eSIM is branded as dtac who are a local Thai provider, so clearly it's local), but often it's not (eg, their US eSIM is from Change who are not a well known US provider - but given it apparently uses both the T-Mobile and Verizon networks, odds are that it's a roaming provider!)