Sometimes that's true. I used to have a Tandberg R2R that had a built-in phono preamp. This preamp, as I was later to realize, was far, far better than the phono stage in my 1972 Altec-Lansing receiver, through which I normally played my records. The Tandberg architecture enabled me to record directly from the turntable into the tape machine. Doing a line transfer also--as you mention--took a lot of room-borne noise and vibration out of the playback, so the net result was that the tapes sounded better than my LP playback. Other situations might create opposite results. The Tandberg also had a better s/n than a typical turntable, unlike the Teacs and Sonys of the early '70s, so they didn't add noticeable noise to the signal chain.
LP playback vs Reel tapes made from LP
Can reel tapes made from LP actually sound better than the LP itself? It seems like there potentially could be less acoustic feedback into the analog setup during the recording process. Is this worth the trouble and the extra layer of electronics?