Just a couple of sentences where I'm coming from with my opinion. Maybe I extrapolated a tad too much what I see in Norway among my social circle - mostly DINKs who have worked for about 5 years, and have already long paid off their study loans. Also, electric cars are objectively cheap here. A brand new Polestar 2 is 39.5K GBP in Norway (source), for instance. You don't even get a decently spec'ed 1.5L Ford Focus for that money (source), let alone the running costs for electric being a fifth of fossil cars. There are also not so many used electric vehicles which are spacious and future-proof in this price range. Ioniq 5 might start around 32K GBP here, with "Project 45" being around 42K GBP.45k GBP doesn’t strike me as “young family starting out” territory. It’s only 5k off of the Polestar which is considered to be fairly expensive
What Ioniq 5 has that Polestar 2 doesn't for young couples is space, and lots of it. Word on the DINK street is that Polestar 2 is not suitable for 2 babies' equipment, whereas Ioniq 5 should be enough. It's a similar rationale behind Audi eTron being Norway's best selling car of 2020, not just electric, but overall.
As you said, I am likely wrong to have this opinion in general; 45K GBP is indeed quite a bit of money relatively speaking for the UK. I should have specified that I was talking about the Norwegian market. 🙂