Is there a difference in sound quality when streaming TIDAL Vs CD player

Yes, especially when performing a direct comparison between Tidal and a cd.  Any manipulation of the signal affects sound quality.  Although they claim the feature is sonically transparent, it isn’t.  Just as MP3 was claimed to sound as good as a cd.
The feature is useful for casual listening to play lists as you mentioned so as to avoid constant attention to the volume control.  I don’t listen that way so I leave the loudness normalization disabled.
Since it only takes a few seconds to switch off/on, you can change the setting as needed to match your listening session.

My experience matches exactly what wrenth says.
Red book CDs sound better than Tidal, even Master recordings.

Based on this and other discussions/threads, I think the relative SQ from different digital sources is system dependent.  Not surprising when you think about it, but also means the best way to determine what gets you the best SQ is to listen and experiment.

My experience, which is limited, leads me to the following ranking, worst to best:
- Redbook CDs via Oppo transport and DAC
- Redbook CDs via Oppo transport and PS Audio DS DAC
- Local NSA via PS Audio DAC
- Tidal via PS Audio DAC

Honestly, I am not certain I could consistently tell a difference in blind testing of the last two.

My experience with MQA vs standard files from Tidal is both evolving and mixed.  Evolving bc a couple months ago I declared on another thread that MQA was superior (at least for my system my ears), and then I went back and listened more closely, doing some A/B comparisons where possible, and changed my mind, determining that there is not a consistent difference one way or the other.  My theory is that it depends on the quality of each type of recording.  Some standard files sound better than MQA and vice versa.

Another thing to consider is the connection type - for example, PS Audio seems to tout ethernet or I2I connection, believing this makes a big difference in SQ.  I am sure those who enjoy their DACs without these options could disagree.  There are those who swear that the ethernet cable itself makes a difference (lookin at you, Supra fans!) in this chain.

And like many, the damn fine convenience of Tidal has me looking at but not spinning my cds, except for in the car. And I do continue to buy CDs, for the car and for when the internet crashes (which is rare but still scary), and also to support the artists and the independent record stores.

Back when I was using a CD player for digital music, I noticed definite differences between players and converters.

Since I ripped all of my digital material (using a computer CD drive) to a server and play from that via Sonos to my various systems, I haven't been able to tell reliably that there is any difference between direct playback from the CD player, play by streaming from the network drive, or listening to Tidal high quality.

The slight inferiority of Tidal low quality, Spotify etc. is readily apparent though.

I use a Hegel DA converter.

as a side note.... listen to the DSD of Floyd's . Wish You Were Here... good lawd that ill make you feel like you are hearing it for the second time...