Just how many options does 1 need in a 2 way bookshelf design?

Graham LS5/8.  It may not look it, but that's a 12" woofer.

And now something old that's new from Wharfedale (Dovedale), with a 10" woofer.

Interestingly, the original 3-way Dovedale (1960) uses 12" woofer.  Honey i shrunk the Dove ...

https://www.petervis.com/gallery/Vintage%20Advertisements/wharfedale-hi-fi/wharfedale-dovedale-3.html

If I understand the posters question three way are not necessarily better than two way speakers. However, IMO three way multiple speakers in a tower likely have greater dynamics for a live sound in a high quality speakers vs a bookshelf two way speaker.

Old Jensen 4 way from mid late 70;s rocked with a sansui 7070 at my cousins the i was a kid,

but this was back in 83-84 maybe.

big monkey coffins, but looked wicked, which was the motivation for my CV at15, d9, se380 pairs i had.

now a days must have wiff approval. she approves the energy rc-70. only wish had them in wood veneer.

great bookshelf is energy rc-10 and the BIC America 62 bookshelf.

tweeter needs a good 300 hours to softn and relax, if your patient, worth the wait.

new rc-70;s, i remember took over 400 hours to become perfect, loosen the surrounds, etc etc.

loaded the old sherwood 5 disc carousel, repeat all, went down every other day, after trying to remember what they sounded like night before. yeah right.

don't knock the BIC America 62 bookshelf, great bass, amazing presence from the VIFA tweeters. remember, 300 hours, and I still taped a piece of cut cotton t-shirt over the, they are friggin wicked now.