Recitativo secco and poetry

I know very little about opera, but I think "Recitativo secco" is what opera singers sometimes do between songs - minimal orchestration: more talking than singing. In musicals they would talk.

I can't find much online about the pros/cons of recitative. It can involve a few instruments. "secco" (dry) is the most minimal style. Here are a few quotes -

• "It increases the interest of Scenes which, deprived of the resources of the Orchestra, might become tedious: but it seriously diminishes the amount of contrast attainable in effects of colouring and chiaroscuro" (https://en.wikisource.org/wiki/A_Dictionary_of_Music_and_Musicians/Secco_Recitative)
• secco recitative gave way to full recitative by 1820 in serious operas, and became standard in comic operas during the following decade (New Grove Dictionary)
• "Typically, the earlier the opera is, the easier it is to distinguish between recitative and other operatic sections, such as arias or ensemble pieces" (https://www.operasense.com/tag/recitativo-secco/

In books like Tim Steele's "Towards a winter solstice" the rhyme/meter keeps ticking over even when the poetry's having a rest. In free verse books like "Bycatch" (Caroline Smith) (a good book) there are stanzas (indeed, whole poems) where the line-breaks carry on even though the text is prose. It's like those joggers who run on the spot waiting for the lights to turn green.

So what's wrong with talking instead of (gratuitous?) singing? What's wrong with passages of prose? Maybe

1. the work feels more of a unified whole if the music/form is sustained
2. there is a hierarchy of arts - music is higher than words; poetry is higher than prose - and people prefer the higher arts
3. there's a thin-end-of-the-wedge fear - if you start leaving out line-breaks where will it end? Flash?

Let's deal with those issues in literature -

1. The haibun form is hybrid. It hasn't really taken off - perhaps because people feel they should stick to the rules of having a prose travelogue and a haiku. People are more flexibly combining prose and poems nowadays. However, I don't think the hybrid forms are going to be popular any time soon.
2. Are hierarchies breaking down? Rhyming poetry doesn't have a status advantage over free verse nowadays, but I think that poetry still has a higher status than prose. Flash's status is rising in the prose world.
3. Given the 2 points above, I can see why authors don't slip some prose into a poem, or combine prose pieces and poems in the same book (I think John Updike did it, but it's rare). That said, the border between free verse and prose is becoming more porous, with some writers (Carolyn Forche, Michael Loveday, etc) re-categorising some of their old poems as Flash. I can imagine a day when people who would have produced a poetry book in the past could write a book of Flash instead, using much the same material.