Ehhhhh I don't know about that.
If your judging relevance merely by whether or not they reach the peaks of JT, Achtung Baby or the two early 2000s albums? Then yes, they'll never achieve that again.
But without the embarrassment of the iTunes release? Who knows. Depends on what would have taken its place.
It's easy to forget that just a few months earlier Invisible was downloaded from itunes 3 million times (for free).
So a) the switch from YOU MUST DOWNLOAD IT YOURSELF to WE'RE JUST PUTTING IT IN YOUR LIBRARY was clearly a conscious decision that both U2 and Apple HAD to be aware of, and b) the appetite for new U2 was still fairly sizable as early as February or that same year.
It will be interesting to see if we get any behind the scenes type of info on the Apple decision in the U2 biopic.
Also, you're right. U2 still had/has retail strength. Obviously touring wise, but SOE was in the top 5 best selling albums worldwide in 2017. And the top selling rock album.
As I've said before, one main reason U2 will never reach JT, AB, All That success again, is that rock has been dying a slow death for the last 20 years.
Just for some perspective. Coldplay has been a huge seller, probably the biggest selling rock band, album wise in the last 10-15 years.
So if we look at their trajectory,
2013 - Ghost Stories - first week US sales - 383k
2015 - Head Full - 195k
2019 - “Everyday Life” sold just 48,000 including streaming. Pure sales were a shockingly low 36,000.
In its second week, the album dropped 70% and sold just 15,000 copies. Pure sales were just 9,288.
2021 - Spheres of Shit - First week total of 57,000 equivalent album units, 37,000 of which were traditional album sales.
compared to SOE-
2017 - “Songs of Experience,” U2’s 14th studio album and its eighth to top the chart, sold 180,000 copies and was streamed 6.5 million times, for a total of 186,000 units
Other rock bands that are still putting out new music that are well known, to compare first week sales
Weezer - 2017 - 17,000 2019 - 39,000 2021 - 23,000
Death Cab - 2015 - 56,000 2018 - 27,000
Chili Peppers - 2016 - 118,000 2022 - 95,000
Foo Fighters - 2017 - 127,000 2021 - 70,000
Green Day - 2016 - 90,000 2020 - 48,000
Pearl Jam - 2013 - 166,000 2020 - 63,000
The Killers - 2017 - 50,000 2020 - 37,000 2021 - 25,000
So this is where rock is. You see the trajectory. U2 is still at the top of the heap some 42 years in, for both album sales and touring.