It’s both money and mindset.
However, which comes first is a ‘chicken and egg’ scenario.
Our lives are pretty much like you describe, OP (and I do love our cleaner, in case it’s you! 😂)
We have the money to say ‘yes’ now. So when someone invites us to something, we can go for the weekend and book a hotel room, or we can agree to meet friends for lunch without considering the price too much, etc. I also love hosting events because it’s fun and we can afford it.
I really notice that money is a big part of this because I haven’t always had money and can remember the times when someone suggesting meeting for a coffee would have me recalculating the food shop in my head.
However, what I have noticed (and it’s only my experience) is that, even when we had little money, my friends from ‘middle class’ backgrounds always had that expectation of doing stuff all the time, just a cheaper version. So as a pp said, a dinner party but with spag bol or pizza, backpacking holiday rather than hotel, etc.
It was the mindset because doing things and going places and feeling a part of cultural activities was what they had grown up with and were used to, if you see what I mean. I count myself in this, to a lesser extent.
So we went on holidays to France in a hand me down tent: but the idea of not going on holiday at all wasn’t really there. Because I went on holidays every year so it was a ‘mindset’ to an extent as well.
That’s an oversimplified example, but I hope it makes sense!
I suppose there is also the education level - if you’ve sat in lecture theatres where people are talking to you about museums and cities as if they assume you know them, that they are there for you to access just sort of sinks in.
But all of this is much, much harder to access without the good old ££££, and I think we all know it!
Very interesting topic, though, especially the idea of ‘cultural capital’.