Ryanair vs. Volotea?

A third option is the overnight ferry, does not run daily but saves you a night in a hotel. https://en.tirrenia.it/ferry-sardinia/

We have only flown once on Ryanair. Two years ago, we flew out from Bristol to Alicante on Ryanair, and back a week later on Easyjet. The flights were chosen mainly on the basis of the departure time - the Ryanair flight left later in the morning, but arrived in good time for us to get to our destination. The journeys were virtually indistinguishable, and the total prices within a pound or two of one another. Ryanair had a lower flight price, but charged more for the extras we wanted. The Ryanair flight had a Spanish crew, since they were returning to their home base, having flown out that morning. Easyjet had a British crew. Ryanair (like Easyjet) have a good reputation for punctuality and reliability, although I think with both they seldom have a plane and crew on standby if something goes wrong.

I've flown Ryanair twice, first was around 9 years ago and I vowed never to fly with them again. The second was three years ago and a combination of price, locality of airport and good times made me break my promise. They were much better the second time round and the service was as expected. There really isn't much difference now between flying Ryanair and British Airways economy. As long as you understand the restrictions and rules then there won't be any nasty surprises.

I've never heard of Volotea so can't offer any advice.

Airlines can be somewhat generic when they just last an hour or two.

The real difference is their terms. And the big difference in airlines is when you're flying long, long distances.

We flew out of Palermo on Volotea. The flight was on time. We had no hassles. You can print your bordering pass well ahead of time (we printed ours just after we purchased out tickets).

We did notice that the seatbelts were very worn. I’m not a nervous flyer, but the seatbelts made me think....

We have flown both in recent years, and they were the most direct, non stop options available.
Ryanair. The seats were like a molded plastic and did not recline at all. That was the worst part. A few days before our two hour flight,Krakow to Rome, we received an offer that we took. It was for early boarding for 4€ charge. It was worth much more than that! I would only fly Ryanair if they were the only non stop to my destination.
Volotea has easy check- in and the fight and aircraft reminded us of Southwest. Easier than Ryanair. We flew Bari to Palermo avoided flying through Rome with a layover. I would fly Volotea again. We paid to chose seats in advance and for baggage. They service smaller cities in Europe.