I've never had an issue of an Airalo eSIM flat out not working after the initial setup, but I did have a poor experience my first time using one in Japan a year ago. Their eSIM from Moshi Moshi was painfully slow to the point that Mrs. Majuki and I were using the 256 kbps data from our T-Mobile plan for faster data. Airalo coincidentally reached out proactively via e-mail, asking for feedback after my first eSIM purchase, and I replied saying I was less than satisfied with my experience. Airalo assured me that they were changing their roaming partners in Japan, refunded my money, and extended the validity of the eSIM. When we returned to Japan in January for a few days prior to coming back to the US, the service was noticeably faster.

I'm the same with a prepaid 3 UK physical SIM. I bought it in January 2020, and amazingly it was still active by the time I got back to the UK in September 2021. Since the SIM gives 4 GB of data for 30 days for £10 and includes service in many European countries, I continue to use that. If I'm not staying in the UK I'll either stop by a store on a Heathrow connection or get a local contact to purchase a top up voucher on my behalf.