I think it's what you buy not where you buy it really, in a way- I'm early 30's, consider that that is relatively pretty young and still buy in Zara and Asos. They both have younger ranges which I wouldn't find wearable but equally I think both, especially Zara, sell a lot of clothing an 18 or 20 year old wouldn't go near with a barge pole and both sell plenty of basics and nods to trends alongside their more fast fashion pieces.
Otherwise I shop frequently in H&M, Mango, &otherstories, stradivarius occasionally, Topshop for jeans lately I like their Editor ones and the slim mom jeans and the odd top or dress.
I don't look at Hush, Boden, joules etc and find it resonates with my style at all, my DM shops in them so that is perhaps why but it isn't for me.
As a rule my general day to day outfit would be straight cut or slim mom style jeans, something tucked in (shirt, jumper with rolled up sleeves, t-shirt), gold layered necklaces and trainers/sandals/boots weather depending. The same but a t shirt and oversized blazer if I need smart casual or add low heeled sandals.
Dresses wise I'm enjoying smock dresses and midi dresses with sleeves for this in between weather and layering a jumper over if its chilly.
Tops wise my go to are shirts, tucked or tied at the waist, 3/4 sleeve breton or and I've been getting into the shirred square neck tops for summer, with a slight balloon sleeve. Really peps up a pair of jeans or shorts and sandals.