Quality coffee fell out of favour when instant coffee came on the market. Before that, it was common for people to roast their own coffee using a stove-top pan, but instant coffee meant that anyone could manage to have a coffee-like drink without worrying about roasting and the occasional fires that can result (it's quite easy to set fire to the chaff released from the beans). When people grow up with instant coffee, they often don't realise the difference until they're exposed to expensive coffee-shops.
It's a similar situation with tea as most people don't appreciate the staleness of tea-bags bought in supermarkets until they're given a quality loose-leaf brew. However, tea wasn't better back in the day as it was often shipped in bricks.
As an anecdote I would have never expected, English Breakfast tea standards are the poorest: broken leaves that fall apart while producing finer sorts.
I think English Breakfast tea leaves are deliberately broken when processing as it gives it a stronger flavour (might help it move around inside a teabag too). Tea leaves are oxidised to make black tea (as opposed to green tea) and tearing the leaves is sometimes part of that process to speed up oxidisation.
It's a similar situation with tea as most people don't appreciate the staleness of tea-bags bought in supermarkets until they're given a quality loose-leaf brew. However, tea wasn't better back in the day as it was often shipped in bricks.