Kenwood’s 72x TrueX multi-beam CD-ROM was very fast. Its speed was particularly impressive when reading the early part of a disc when the rotational speed was low. But it had its limitations and only worked properly on certain types of CD. [IIRC there was a very good review on CDSpeed2000.com - which should be available on Archive.org.]
Factory-pressed CD-ROMs and some types of phthalocyanine CD-R were fine. But it handled audio CDs very badly and struggled to read most CD-R (especially cyanine & AZO, but also lesser quality phthalocyanine). Often it was unable read all the way to the end of the disc. 80 minute discs were a particular problem and it seemed unable to read CD-RW at all.
With this in mind, it seems likely that adapting the technology to the smaller track pitch & pit size of DVD (never mind BD) would have been an enormous (perhaps insurmountable) problem and required a large investment. But even back in 2000/1 it was obvious that optical drives were rapidly becoming commodity items with prices plummeting to the point where there was minimal profit. And with the price of writers falling rapidly, the future of read-only drives would have looked especially bleak. As far as I can see, incorporating the multi-beam read technology in a write-capable drive would have required a second OPU with conventional optics.
As far as I am aware, the Sony Blu-ray cartridge drives nixa_mk mentioned use multiple single-beam OPUs to read/write multiple platters as once (as HDDs do). Whereas the TrueX multi-beam technology Kenwood used split a single laser beam into 7 beams directed at different points the same disc (positions fixed relative to the OPU), with a multi-beam optical receiver & associated controller somehow managing to make sense of 7 simultaneous (non-sequential & overlapping) data streams.
What I would have loved to see was an optical disc writer with a second independently positionable OPU positioned opposite the main one (~180°). In principle a disc could be verified (read back) during the writing process, thus saving a lot of time (& lost data among the ignorant masses). The writing side of the drive would act as the master and control the rotational speed. The secondary read-only slave side would just need a reasonably-sized buffer to hold the written data until it has been verified and a controller able to adapt to any changes in the rotational speed dictated by the master. This should have been possible using the technology readily available 15 years ago.