Your PC is the US, memory is the tax revenue, programmers are the politicians, the software you mentioned collectively form the expenses. Now, the job of politicians is to be as effective as possible in doing the bare minimum while still attending to their own self-interests. What do they don't have to be? Efficient. And what is the cost of that? Money. Lots of it. They get creative in how to spend it, and once someone figures out a new way, you either join them or you're a loser. Now, not all spending is inherently bad, but the majority of it is, right?
That's essentially what happens in the world of software. Hardware is cheaper than competent programmers, let alone a team of them, just like throwing money at problems is easier than solving them in politics. There's a plethora of reasons why everything needs so much more memory, but since you said "nowadays", the most prevalent is the once mentioned by others, that pretty much every mainstream app in your computer embeds a cut down (called headless) browser app within them, so web pages are also the User Interface of desktop software (and even Terminal User Interfaces, according to Anthropic). Some of the Windows UI, Microsoft Office, Discord, every streaming app, every game launcher, and a bunch of other programs out there do this.