Definitely not. Sound quality would be as good as the best FM quality, if that's good enough for you. I would assume Sonos would be much better quality.
Just throwing this out if you're wanting to stay cheap, I use this to listen to whatever the fuck I connect to it while I mow the yard through 3M WorkTunes Headphones (also highly recommended, get the BT model, pay the extra). Has about a good 300 yard distance but my brother in law could pick it up in his PU a 1/4 mile away. Just gotta find the unused FM station location on the dial and use it. Same technology they use at the Drive-ins or how the mega xmas decorators get their xmas music into your car as you drive by. Bluetooth doesn't hold a fucking candle to this. Boom box, receiver, whatever, doesn't matter as long as it gets the full range of FM channels, it will play it.
I guess the one I use is no longer available, but this is from the same company
https://www.ebay.com/itm/Signstek-FM-Transmitter-Long-Range-Stereo-Broadcast-ST-05B-Dual-Modes-0-1W-0-5W-/193655908160?hash=item2d16caa740%3Ag%3A2o4AAOSwZsxc76m1&nma=true&si=cLKM4QOTmzVXzaJ7dnT0ieO2xzY%3D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557
this is similar to what I have
https://www.ebay.com/itm/0-6W-LONG-RANGE-WIRELESS-FM-TRANSMITTER-CHURCH-SCHOOL-DRIVE-IN-free-shipping/143663499562?hash=item217303092a:g:uNkAAOSwUD5exIE2
I bypassed the battery though, and connected to a USB 5V switch directly so theres no charging bullshit involved.
FM vacant channel list by your area
https://radio-locator.com/cgi-bin/vacant