The Premium Economy tickets (slight upgrade from coach, but about $300 pp extra - wider seats, more incline in seatbacks, other minor perks) that I bought for late spring flights to Paris and home from Dublin were about $5,100 for my family of three, more than the entire cost for my week long trip to Orlando earlier this year. I would have loved flatbed seats, as even in Premium Economy I won't be able to sleep, but that would have been a total budget buster, and I wouldn't have even considered the trip. I dream of those flat bed seats though. I'm with you MillauFr. Sounds like a lot of the other posters can fly to Europe much more economically than we can. Maybe they look for special deals, etc. for places that look fun and have some great options from home airports. They are probably fine with coach too.
For us our one time European trip is to specifically hit two bucket list places for DS, so it's not like we are substituting a great travel deal to XYZ etc. Our home airport to my knowledge is pretty dismal when it comes to economical options for European destinations. We had WOW airlines for a while, which had some good prices (would have saved a good $700 or so pp from what I paid for premium economy if they were still around), but they left our airport, and I believe now went out of business, leaving other cities too. To either WDW or Europe we tend to go at prime times when the weather is nicest. For WDW/Orlando that is usually early spring and often for us I can use airline points for that. Regular coach is totally fine, as my direct flight is only 2 1/2 hours. Air pp round trip is about $300 Orlando vs. $1700 (Europe which includes premium economy upgrade). It may be prime time, but flight prices are still pretty reasonable cost wise or point wise for Orlando. For us this rare European trip is late spring, maximizing chances for nice weather for hanging out in cafes. The flying time and airfares though for us are super pricey to Europe, and I don't have airline points for that. I sprung for Premium Economy thinking (based on some previous experience getting a free upgrade on a long haul flight to Hawaii once) that even the little extra space would make that long haul flight a little more pleasant. This fit into my budget, but I had to set what I consider a really large vacation budget to have this European trip happen. And (what a weenie I am), although I think the trip will be really fun, I am dreading those long, long haul flights -- really hate those. Our long haul flights, though, are listed as being on one of those 787 Dreamliner, and both DS and I have always wanted to fly on one of those (so that at least is pretty cool).
Not meaning to talk up WDW. Just saying for some of us Europe is expensive. We did South Dakota this past summer (enjoyable trip) and that was about the same price as Orlando/WDW for our family. Am considering Estes Park / Rocky Mountain National Park as a future late summer trip - maybe 2021 (love that as a late August destination) and that comes out for us to be about the same prices as Orlando/WDW too.