Well I was not expecting to chat about Staphorst on here. I do think if this is the next historical costume online obsession (not you individually Bani just the costube community) they need a similar vintage style not vintage values tagline. Although it will be difficult to separate as they still dress like that in Staphorst so you can't cry time makes for attitude changes. They are orthodox protestant Christian and have very regressive values. It's hell to grow up there if you're gay or a woman with ambitions beyond being a housewife. It's not quite the Amish as they do embrace technology (but not for example cameras) but it's not far off with very oppressive social control. Currently GPs in the area offer off the book appointments for vaccinations because if it's known someone got vaccinated they'll be shunned
So, yes, it all looks very pretty laid out like that on Instagram but my associations are a little different. I have more positive associations with other traditional Dutch 'folkwear', growing up there were still quite a few women (and the odd man) wearing this in Scheveningen. They had lovely sort of jewels that are somewhat shell like. There's still some who wear it now, I believe, but I don't visit Scheveningen proper much.
From a more abstract appreciation, yes it's very beautiful to see, I've come across some of it on our version of tradera, I've attached some screenshots. Beautiful workmanship and fabrics but interestingly enough it's all a display of wealth from our colonial past. This article goes into it (in Dutch, you'll just have to translate it), specifically about the chintz fabric in your picture.
It's an interesting aspect of traditional Dutch 'folkwear' as it encapsulates the immense wealth that was acquired from abroad but that jarred with the strong Calvinist roots of showing off. There's a novel (possibly a film of it too) called The Miniaturist that explores it really well, a good read all round. The audiobook is good as well, it captures the oppressive mood quite effectively.
WRT blazers, IME it's about finding a brand that works well for your body. Joseph secondhand is probably a safe bet, they're basic but well cut so they don't ever look particularly dated or cutting edge and they suit most bodies.