I've helped some of my family members use Airalo eSIMs, and they never had any problems and an overall positive experience.

Recently I decided to use Airalo myself. Upon landing, my phone would not connect to data and I had to rely on expensive Canadian roaming for the day. Later on I found out the issue was that the APN that was pre-loaded when the eSIM was installed is not the right one, and I had to set the "globaldata" one manually. I tried to do this at the airport, but my phone would not recognize globaldata.

Turns out the APN settings in Airalo's documentation omitted some critical fields that have to be set on Android phones (eg., APN type). I had to discover these settings manually to get the SIM to work.