Mainstage is a specific genre of EDM, ironically known for being particularly transparent and banal these days. Some of the most likely to have lyrics that are basically just another beat track, IMO, if they have them at all.
Trance ironically enough (including a lot of the stuff Tiesto worked on) is known for having very deep lyrics and that's a good chunk of what people are missing I think when they make the comments like above.
I'd check out Beautiful Things by Andain if you're curious. The lyrics are about a woman who believes she gave up her life and potential to be a traditional wife and is contemplating suicide to end her regret.
I think once the genre becomes defined, it's often bound to get more simplistic if there are words/lyrics. It's not limited to trance music.
A lot of trance music never even had lyrics; listen to what came out before 2000. (Even Tiesto made a lot of music without lyrics before 2002 or so). If you want to find music that sounds like the early days of trance music then you'll more likely find it labeled as techno music today (which is not really all that surprising since trance music originated from techno music anyway).
Beautiful Things is arguably not trance music. Also, when you're studying or trying to concentrate, do you listen to music with lyrics?
In the last 50 years, you can probably count the number of chart-toppers without lyrics on one hand. Animals, Axel F, Doop, Flat Beat, and Sandstorm (and I am not sure if these even topped charts everywhere).
Sure, if you are into the niche of EDM or techno club music, the situation is different, but none of those tunes sell millions of copies.
It is though. The number of non-chart-toppers with lyrics is beyond counting. You don't make yourself a chart-topper simply by writing music with lyrics
The point is you could spend hours actually developing subtleties in engineering, especially in timing and mixing, to produce something profound.
Or you could get a drum machine and a 303, and get someone sexy to sing/rap/speak over the top, make a video, and save a lot of time. A lot of pop music these days is quite simple, except for the singing, which I can admit is talented, but it's more about personality/fashion than music.
Also, any musician that wants to get big should know that the fastest way is to add words/lyrics.
Music is such a universal language that it needs to be annotated or something.