Maybe they have investments, maybe not.
They don't live the life of people who are comfortably off.
Here's why I think that:
The past year or so they have wildly flitted from one get rich scheme to another, the sure sign of someone who needs to make money.
The majority of clothes they wear are gifted or from normal places like Tesco and ASOS (apart from his little splurge on the vomit jacket and the LV scarf, which I think we're 100% motivated by the fact he thought he was going to make a fortune on the book, so he spent it before he made it)
There one and only holiday this year was to a standard place in Spain that is accessible to most people and it was a freebie. They don't go anywhere else unless it's gifted, not even days out. People with money and the school holidays they have would have at least 2 holidays during the summer break and to more glamorous and exclusive places. Anna and Jono are the kind of people who would want to be hob-nobbing with the beautiful people, so why aren't they doing the ski trips, the trips to the Maldives, mini breaks to Sorrento and St Tropez etc? They didn't even have a night away in a posh hotel for their anniversary this year!
And as for not wanting to be out and about too much because of the attention, Jono lives for attention
The house needs some serious work before selling. Who in their right mind would put it up for sale without doing even the minor stuff like painting the front step? The garden is ruined, on the vlog for A2's birthday the lawn is absolutely knackered. I know it's been hotter down south, but people in a house that size would have a garden and lawn maintenance company coming in regularly. They aren't doing anything to sort the house out because work costs money.
They now have virtually no staff, barring Izzy doing stuff sporadically and the dog walker. The cleaner is still there apparently, but seems to be off on holiday a lot (maybe she's the one going to expensive resorts
)
The kids don't go to summer camp anymore, in fact the kids don't do much at all.
They just don't appear to live the life of people raking the money in. Now you might argue that they are being savvy and those material things don't mean anything to them, but that would be a big lie. Look at the way Jono tried to reframe the courtesy car as Anna's new car. How long did it take to get those flipping car windows fixed? Rich people just wouldn't put up with that, especially not living where they do. They both like material things, so the only explanation is they are struggling.
I still believe, however that he will do some grand gesture and buy something even more expensive just to save face in the short-term.