I've been using Tidal since its launch in the UK, and used Qobuz before that. Quality wise, played via digital out from a Sonos ZP 90 into my Musical Fidelity kw250s, I really struggle to tell the difference between Tidal and CDs. For me, it's like having an enormous CD collection, with new releases being added all the time. I haven't been buying CDs since I've had Tidal/Qobuz - it's now just the way that I listen to music; not just trying out things I might want to buy.
For 'on the go listening', 4G is sufficient for CD quality FLAC streams (when available) and it's so easy to mark and download music for offline listening from your phone.
I take the points about it being dependent on Internet reliability. I've got an 'up to' 300 mbps cable connection but still been having some problems with dropouts. But I've still got a big collection of CDs so I'm never without anything to listen to on the rare occasions when the Internet connection is playing up.
Tidal is now promising higher than CD resolution streaming through the new MQA format, which is quite exciting.
The downside of Tidal, for me, is that it heavily promotes certain styles of music that are not of interest to me and does nothing to present the music I like (and I've got very wide musical tastes). On most occasions, the music is there; but you have to find it. I really don't think that Tidal is making the most of its vast catalogue in this regard. I don't think it would be that hard to adapt user home pages to the types of music they've elected to be informed about?
Qobuz suited my musical tates much better in this regard but had a very French flavour running through it. I'm not sure if this has changed any while I've been with Tidal?
I'm considering switching back to Qobuz but being held back, partially by inertia, and partly by the prospect of MQA on Tidal. But one thing's for certain, I won't be going back to buying two or three CDs a month when the same money buys me pretty much anything I want to listen to, at the same quality, at the touch of a button.