I hope that I don't seem like I'm backpedaling here, but while not everything there is worthwhile, and I do think the whole "clearly it's better because it's a huge resort blah blah blah" is overblown, it really is the stuff outside the parks that sets WDW apart from the others.
There's so much there: exploring the hotels, going to the water parks (which are extremely underrated in terms of theming and design, and perhaps the most pure thematically in the United States), watching the hokey but charming Electrical Water Pageant that still soldiers on unaltered from the 70s, eating at a beautifully themed or wonderfully atmospheric restaurant tucked away in a hotel (DLR has some of this, but WDW definitely has more of them), things like the Hoop de Doo Revue dinner show and the Cirque shows. Disney Springs is away from the parks but is many times the shopping and dining hub that Downtown Disney is in quantity and quality. The mini golf courses are fun diversions. Taking the monorail around the monorail loop and exploring. Hiring a boat and going out on the lake.
All of that is part of the WDW experience. That is often why when WDW people come to DLR for the first time they spend a lot of time talking about the shortcomings of DLR as a resort, because that so defines what WDW is. Because honestly there's very little reason to go to DLR if you're not going to the parks. By contrast, while it's not how most people do it, you could conceivably go to WDW for a week, never set foot in one of the main theme parks, and still have a wonderful trip that was packed with activities. The shortcomings of the parks stick out less because there's so much going on there, and the parks are only a part of it.
Of course, time, money, and interest are finite, but WDW really is its own beast and needs to be approached differently from the other resorts around the world. If you or anyone else accustomed to DLR went to WDW and treated it like you treat DLR, your vacation would be a failure, and of course the opposite is true as well. Each resort has its own strengths, and should you go your trip should be tailored to embrace those strengths.