I recently returned from a 2.5 month trip in Italy. For the first month, I used Verizon's international coverage ($100 supplement to my monthly bill, coverage worked exactly like it does at home). For the second month, I used the Airalo app to purchase an eSIM. I have an iPhone 13.
Coverage was excellent. I was in Venice, Udine, Milan, Stresa, Mantua, Modena, Florence, Rome (didn't go any farther south than that). I liked that the eSIM automatically selects the best network from a variety of providers (Vodaphone, TIM, Wind) based on which provides the best coverage where I am. I purchased an Italy-only eSIM, so it did not work on the day when we crossed over from Stresa to Locarno, Switzerland. (For that day, I disabled the eSIM and switched back to my Verizon physical SIM and purchased the Verizon $10/day travel pass.)
My eSIM was for data only, meaning that it did not cover calls or SMS texts (because iMessages are sent/received over data, I could text or FaceTime anyone with an iPhone). It obviously worked with all my apps (Google maps, instagram, email), and I could use it as a hotspot to connect my laptop and/or iPad while I was working. The main downside of Airalo is that I did not have a separate Italy-based phone number. My phone acted exactly as if I had it in airplane mode, but with wifi (except instead of wifi I had an eSIM).
I initially purchased a 10GB plan for $16, which was valid for 30 days. I used nearly all of that and before it expired (end of 30 days). I then topped up (extremely easy to do) for another 5GB for $11, also valid for 30 days. I used 3.5GB of that, and then my trip was over. Since I was using my phone as a hot spot, I'm sure I used more data than the average person.
I did get hit with some additional charges until I figured out how to completely turn off my Verizon SIM (because SMS texts were still pushed to my phone). That was entirely my fault - Airalo provides excellent detailed instructions, I just didn't follow them properly. Once I did that, no problem.
Hopefully this was somewhat helpful - I'm not tech savvy at all, but I'm happy to try to answer any questions if you have them! Have a great trip!