I'd add the guess. First time parents being older or more to the point the reasons they wait.
Part of the desire to leave child raising until people are more fiscally secure. (hardly something we can blame younger couples for over the 2020s). Will be that the cost of nappies was often a huge motivator to young, less stable couples in the past. Now it hardly seems like the big cost compared to housing etc nowadays. Back in the 90s when I was at that point. Rent etc seemed high as an expense. But compared to income today, it really represented a much smaller % of every day costs. So other things were more influential.
Looking on Amazon. Nappies actually seem cheaper inflation adjusted then in the 90s.

True. But foreign students have always been a huge amount of UK university funding. Basically from as far back as the 1800s.
Limiting them is not the solution. Nor is it the cause of diploma mills. Reduction in government funded research grants is what forced uni to move to tick box education. And government desire to avoid administration costs is what leads to Unis without the strong educational ethics taking advantage of it.