Take this what I will write with a bit (or a lot) of reserve, as this is just what I have heard from two friends who are running Sram's XX1 Eagle for a while, and not what I have been experiencing myself. Thing is, 1x with Eagle might be super cool to drive, but based on comments I got from these two guys, it's also super expensive. They make around 5-6.000km/year and they go through 3 chains (3x 90eur), 1 to 2 front chainrings (1-2x 100eur) and 1 cassette (400eur) in a season. Considering with my investment of 30 to 60eur for Shimano XT 11 speed chain (depending if I change 1 or 2) on my 2x XT setup, their maintenance budged is pretty high
Now, as I wrote, take with a grain of salt if this usage of spare parts is real or not. I don't see reason they would be lying to me, but still I wouldn't really grant anything it's 100% accurate.
But considering I hate Sram from bottom of my heart, and will never ever be on any of my bikes anymore, this what they told me fits me fine
And if it's really like this and you need to spend almost 1000eur/season for spare parts, Shimano's XTR Di2 doesn't sound expensive anymore. And I would take Di2 over 1x without a second thought. I have been riding it once and I simply love it! Ok I don't love it enough to be ready to spend such ridiculous amount of money for it, but still