Going to Switzerland, Italy, Austria, need affordable reliable (and affordable) eSIM

Going to Switzerland, Italy and Austria this year. was thinking of getting a Europe region esim instead of individual ones. Been looking esim providers on esimdb. it's a great site but the prices vary dramatically. I'm looking for something around 20 - 30GB for 17 days. I was looking at esimfly.net their 20GB for around $9.00 USD for 30 days and seems to cover the countries I'm visiting. Are they reliable? There isn't many reviews of them. Their pricing seems extremely affordable compared to others where they go for $15+ for the same amount of data and days.

Then there is the other recommended ones I read here in the esims subreddit, such as Airalo, Ubigi, which are way more expensive. I've used Airalo in Japan last year, it worked great and for Japan it was a decent price, but for Europe, it's expensive.

What are some of the reliable and affordable providers that folks have used?

Also, since this will be my first trip to Europe, what are your opinions on getting a phone number? I have WhatsApp, it seems to be the go to messaging app over there. is a phone # necessary?