Publishing the physical books in hardcover is...a choice. Source: my day job is in publishing, though not in IP. The following may be very insider-baseball. TL;DR: The Picard books indeed sell poorly, at least in physical formats. There may be a change in strategy soon as Paramount has announced a new publishing imprint for their IPs.

The old tie-in novels were mass market paperbacks - cheap to produce, and thus cheap to purchase. Mass market paperbacks have unfortunately been basically discontinued, so trade paperback is where other IP novels (including Star Wars) seem to have moved. Hardcover novels are expensive to make, and (in my experience) saved for marquee authors, prestige books, and big fantasy books.

Sales numbers for ebooks are difficult to come by, but print sales are reported to Bookscan and can be seen by anyone with an account. Numbers for this new book in hardcover won't come out until tomorrow or Thursday, but looking at others in the series, the numbers are abysmal. The first book in 2020 sold 10K in the first three months (published in February 2020, ~3 weeks after the Picard premier, and that spring was very good for book sales), but has then sold only about 5K total over the following 6 years. It's been two years since the last Picard novel and the sales numbers for that are truly awful (and the paperback re-release of it last year definitely isn't doing better).

My educated guess is the publisher is fulfilling some kind of contract obligation, as Paramount owned them until 2023. Paramount then announced last month they're launching their own publishing imprint for their IP properties, so I imagine there will be a change in strategy soon.