Online, there are almost no physical hardware stores in my country, and all of them target a very specific segment of laymen who have no technical understanding of things, in other words, they sell old tech at extremely high prices.
That has become true for the UK too, almost.
You can still go into a physical stores (John Lewis, Currys) and buy a prebuilt PC or laptop but Currys in particular will pressure people hard with upsell for junk services they don't need. Those add-ons are close to worthless since the retailer is
legally obliged to do 95% of what the upsell offers as part of consumer rights and UK sales laws. They're preying on people's ignorance and I know from someone who used to work for Currys that the upsell is commissioned HARD. If there was ever a reason to avoid going to a store in person, it's pushy sales people who have an agenda that works against your own interests.
Argos is at least an option where you can buy a laptop as a sealed box, but you're not going to see it on display, you just pay for it blindly and you get your sealed laptop box from a counter once someone has dragged it out of the warehouse behind the counter. I've done that if they're cheaper than online for something, but it's rare - and I have to make the effort to drag myself to one of their stores or back, and I value my free time at double my effective hourly rate at work, so it needs to be a sizeable discount to beat "next day free delivery".
Online and used.
I only get something from the store if I need it immediately like an ssd or sd card, wifi stick, stuff like that.
Commonly-needed essentials exactly like you've just described are being covered by Amazon same-day in most UK cities now. Unless minutes matter, I do that because the brick-and-mortar stores will offer those things at a ridiculous markup. MicroSD cards and cables are often 2-3x the price of online retailers. HDMI cables and USB cables are the worst offenders at probably 5-10x markup. You've clearly made the trek to their actual physical store because you're
desperate and they know it.