There are usually clear differences between bikes at all price points... although in some cases this may only be 'goodwill' that the frame manufacturer has accrued via its reputation as a sponsor of a top team, or as a boutique brand.
Very generally speaking, once you get to a price point that gets you a carbon frame (>£1-2k) you'll find cheap alloy finishing kit, low end components, and bog standard wheels.
For the vast majority of riders this is absolutely fine for their riding needs, but we're not a society that simply buys what we need, we also buy what we like, what makes us feel good, and sometimes (depending on our individual psychology) what impresses our peers.
As the price increases, so does the quality of all those additional bits. Are they 'necessary'? Probably not. Are they desirable to a lot of folk though? I'd say so.
In 2009 (when I was first starting out) I spent £1k on a Boardman Team Carbon, that was an absolutely cracking bike. Over the course of the following years I had replaced the entire entry level SRAM Rival groupset (that was perfectly fine) with SRAM Red components (because they were lighter and smoother), the alloy bars and seat post with 3T carbon (because they were lighter and fancier), and upgraded the wheels to some deep section Fulcrums (because they rolled better and the freehub made a lovely clacky noise).
The bike should have been perfect, but it wasn't (for me), because it still said 'Boardman' in big white letters. So for probably zero performance gain I bought a second hand Cervelo frameset, some even deeper section wheels and swapped everything over.
For some people, the Boardman branding wouldn't have been an issue... and it's not an issue to me at all, generally. I still have a Boardman CX bike that I use in the winter, I bought the wife a Boardman as a first bike last year. I actually think they're great, and superb value for money (especially in the early days). But I always aspired to have something a bit 'fancier', or perhaps a more established name that felt a bit more 'accepted' on the club ride (not that anyone ever said anything negative about it). And also (and most importantly to me) that gave my loins a little flutter when I thought about going for a ride on it.
It's this aspect of my personality that's driving me in my planning and saving for a titanium build that will ultimately replace the Boardman CX as a winter/tourer/commuter bike, relegating it to a gravelly pootler. I won't be spending £10k, but I'm potentially spending eyewatering amounts, if I end up going down the custom built frame route.
The caveat is that this will be a bike for life. Titanium frames don't really change with fashion in quite the same way that carbon ones do. If you spend £10k on this season's aero frame, it might feel old next year when the new trends emerge. Look at the discontinued Venge, for example. Other than disc brakes and slightly wider tyre clearance, has there been much movement in titanium frames in the past 20 years?
It's not for everyone, but I don't have any negative feelings to anyone spending their hard earned cash on whatever bike that makes them happy. Well, maybe jealousy.