I'd mostly agree with this.

D-VHS was essentially the same as DV or Digital8, with digital signals stored on the tape. No analog info was present, and was not subjected to loss. But unlike DV/D8, it wasn't lossy DV (4:1:1) but lossy MPEG (4:2:0), which had less/different colorspace compression. The signal was superior, due to the codec.

Note that D-VHS bitrates went from about 3mbps to 15mbps, so my "agree" would depend on it being 15mbps. Anything less than 10 is DVD territory, and looks the same. I've long stated that 15mbps is a sweet spot for both capture and archiving, for MPEG-2. It looks near-transparent to the tape source. Only for technical reasons (GOP, maybe 4:2:2) would you want lossless for editing and restoration.

However, it was still helical tape, which let to problems. That's the main reason the format was disliked, aside from cost.

D-VHS was closer to MicroMV than anything else. Excellent format (MPEG-2 based), terrible tapes, but too expensive. (We have a MicroMV camera for transfer work, what few come in.)

Was there ever a good quality video format on non-helical heads?

D-VHS in the HS mode (SP speed of regular VHS) were able to achieve better-than-DVD quality and were capable to record in high definition in that mode in 28.2 Mbit/s. Standard definition in STD mode (LP speed of regular VHS) was in 14.1 Mbit/s. Only the LS3 and LS5 modes (the number is the multiplication of the regular time of tape), something like SLP and EP modes in regular VHS went on lower bitrates.

The LS3 mode was more-or-less equal quality to DVD.

So it was far superior format to the DVD, nearly as good as BD.

The failure of the format lied in increasing popularity of DVD and poor marketing, though conveniancy of the format was the final nail to the coffin (nobody liked to rewind the tape after use [though Video2000 was the solution to that with superior video compared to VHS, pity it never got Hi-Fi stereo]).

Well, I guess the mechanism of several stationary heads could be utilized, like on computer sata tape storage, but there was no point for that.

No one doubts that what you speak of is decent quality, but it leaves a long way to go when it comes to the feasibility of playback, media manufacture and distribution, transmission, and the many vicissitudes of the marketplace. Everything digital is a step down from master film production anyway, and the best way to view digital movies these days is still the projection-oriented movie house (which unfortunately has taken a step down from film projection).