Nothing to do with superior technicality IMO. Just better put together teams. It's all cyclical. From 2005 to 2012 there was an English team in the final every single year, except one; and 2 or 3 English teams in the semi final. But no-one was saying it was technically superior in the premier league.
Real and Barca just have an insane pool of talent, and Simeone has done an incredible job. He'll probably end up in England within two years. Sevilla have done well in the Europa League, a trophy English teams have never taken seriously until Klopp made a proper play for it last year (and got to the final).
They have better teams right now. But the whole 'technical' argument is just smoke and mirrors.
I can see that Spanish players are generally better on the ball than English players; but how many English players are in the first XI of any of the top half teams? Not many. And those that are, are generally pretty technically proficient. Look at United's first XI - Zlatan, Mata, Micki, Martial, Pogba, Herrera, Blind etc. Huge technical proficiency. Arsenal - Chocked full of technique, included superstars from La Liga (Sanchez & Ozil). Can't be bothered to go on.
It's the pace of the game, and the physicality permissible in England that diminishes the role of technique. Not the players.
It's like you're answering yourself, if you go to mid 00's EPL top sides and compare them to their current rosters we all could die of laughter comparing the technicality and talent
United had: Scholes, Carrick, Ronaldo, Rooney, Tevez, Giggs, Nani, RvN. All in their prime or near to their prime version, current United squad still has quality, but nowhere near to what those guys where at that moment, a lot of potential, some good "peak" players but only Ibra and maaaaaaybe Pogba would stand a chance against one of those guys if you take their current level and put them in a 04/08 United squad
Chelsea? who in their last squads would make Ballack, Lampard, Robben or Drogba break a sweat to claim their spot? Maybe Hazard (2 years ago, not his last year version) and Costa would have a looong chance, but to me they are a class below those guys, I could even pick Joe Cole, Duff or even Sheva before Pedro or the other guys
Arsenal? From Pires, Henry, Vieira, peak Fabregas, Bergkamp, Ljungberg... to Sanchez, Ozil, Giroud, Welbeck, Cazorla, Coquelin... I want to cry
The only improvement would come from the 4th EPL "seed" if you swap Liverpool for City, but then you have the fact (because it's already a fact) that city are just Bottlers at European level.
English clubs would take a great leap forward if they were able to lure top quality from other leagues like they did in that era, if you start picking away players from PSG, Bayern, Borussia, Atletico, Juve like they did 10 years ago then yeah, surely they would be better with Verratti, Malouda, Krychowiak, Cavani, Griezmann, Koke, Kroos 3 years ago, Thiago, Douglas Costa, Aubemeyang, Reus, Gotze, Dybala... and even baiting sub players from Barcelona/Madrid like James, Isco, Arda, Rakitic/Andre Gomes... but that's no longer the case so as talent appears in teams that weren't a factor 10 years ago if you're not Barcelona/Madrid you're bound to suffer a little more