Of course company cars aren't free, but many jobs require them or are much easier to do with them. I have a company car because I need a car anyway, and getting a company car frees me from having to go to the office to pick up a pool car, or book a hire car every time I drive somewhere for work, which is generally once or twice a week. We have no car allowance scheme and use of own cars is seen as a last resort and generally not allowed. Massive hassle, waste of time and mental load I can do without.
I don't care about status, my cars a Skoda anyway and I just need a reliable car and to me this is a cost effective, time efficient way of sorting it. If I didn't have a company car, I would have a sub £1000 car that I would regard as disposable if I had an expensive bill.
Old cars are fine if you don't travel all over the country so aren't faced with it not starting when you're setting off to an important meeting 100 miles away, or it breaking down while you're out. I'm not saying old cars break down all the time, but it's more likely.
Over the last 20 years, I've usually had company cars, apart from when I had the PCP and DP has usually bought his own, but I would be fairly confident I've spent no more on cars than him, because his cars have always needed money spending on them, and there's the cost of tax, insurance and breakdown, which I've generally not needed to pay.
What I'm saying is that unless you know the person very well and the ins and outs of their bank account, you have no idea whether their car is appropriate to their means or circumstances. We already own a house that is nearly paid off and plenty suitable for our circumstances. I also have a very good pension and savings, and can afford several holidays a year. We have no DCs so have no university/inheritence etc considerations and I don't give a fuck whether anyone thinks I should be spending more money on a house instead.
Of course some people are spending unwisely on cars, but people spend unwisely on all sorts of things.
(Re renting in Spain vs buying in London - tenants have vastly more rights there, a lot of UK people are 'obsessed' with owning property because the rental market is so shit and expensive, especially in London, I would have thought that was obvious to your Spanish colleague now that she is presumably experiencing it first hand).