I encountered the same mechanic when working on my Tapestry Monument.
The tl;dr part of this is : it’s a surprise because the lily and sunflowers are “Plants” and the Frostsnaps and Brightbells are “Resources”.
I had purchased the lily and gotten some sunflower in a trade mission, I guess I thought they would be potted – or plants, not individual flowers even though I had played the other clan previously – I did not watch what came in when I purchased things from the trader.
After I bought some brightbells and used half for crafting, I had to stop skilling up my Herbalist once I started purchasing the Brightbells from traders while accumulating the Frostsnaps and remainder of Brightbells. This took 1-2 in game weeks.
Thinking about it lore-wise, I don’t mind having to do this because I’m in a desert getting non-local flora, and I want to finish the monument as soon as possible (because I don’t know any better, it’s a quest sitting there in my quest log so I figure I need to do it right?). I didn’t know that later I can trade for seeds, I didn’t even have a farmer yet (I play weird).
When I did the quest I thought ‘it’d be nice if these were like the Fox Lily and Sunflower’ and were quest items – not just harvested flowers, but then that makes them more rare, I suppose. People who DO farm and can grow them would have to buy them instead of just harvest them.
I also thought ‘Hey a chest where I could store them would be nice’… A place just to put objects that I did not want to use and save them for later. But that’s a lot of coding that does not really fit with how objects are used in the game as it is.
A ‘really nice to have’ might be some sort of toggle on the craft screen to pick what flower to use but that again might be overly complex when it makes more sense to just endure a little hardship in the desert for a few in game days (it was maybe 2 game weeks tops by the time I’d gotten all the pink and blue flowers through trade?).
Anyway, much later and in retrospect, I don’t think it is a big deal … and I do know I am rambling about this. I’m now up to Growmun 16, I finished my monument maybe 2 in-game months ago, and I have not built anything yet. No buildings. So next game I probably won’t rush the monument? (Terraforming takes long.)