The country is growing in every aspect, bar the sporting one. And this has nothing to do with the EU, as the change started happening already in 1990. It just took 15 years for everything that was built in the prior decades to fully crumble. All results in the 90s and up to Athens was the last pipeline, that was structured in the old system.
The truth is, like JoshMartini mentioned, that sport funding, country wide structuring and people's mentality completely changed in one day after the old regime fell. The next day and upcoming years no one was thinking about sports as an important issue. On the contrary, it became the bottom of the barrel. Which is true to this day still. Every time there is a new Government, in the 20 or so Departments, that are structured, the Sports one is always not taken seriously and the sports Minister is looked like a joke amongst the rest. There were even years, when there was no Sports Ministry and sports were added as a backburner in the Education or Youth Ministry.
Regardless of the money aspect, i have talked in length before on the old system and how it will never be duplicated.
In those days, for every kid, from every town and village, it was mandatory to do sport already from 1 grade. Lots of sports, after school sports, not your typical 2 hours a week killing time, like in the present. Then there were agents, or a special committee, that had a job to go to every town, to every school and scout the best children and navigate them to which sport will be best suited for their abilities, so that they can start specifically training in their pre-teenage days.
After that they were taken first from the local coaches, again every big town had training camps for a dozen sports, it wasn't just the one camp, where you could go train for gymnastics etc. Then there were selections between the different regions and only after that you were elevated to National team status and get the full system structure.
Nothing like this is being done today. Kids are not only not encouraged to do sports, everything in the system actively tries to discourage them. Any top level athlete we have is purely based on the individual person's desire and a small team around them.
I can also add the notion, that kids in the 70-90s were waking up and going to bed with only the thought of playing sports. It doesn't have to be on an organized level, just your regular play with friends. You couldn't find a street, where the neighboring children weren't playing. Even in my teen years, in the mid to late 00s, you had to wait your turn for a football field in my school, even though there are 5. Each of them were always taken, from schoolers to people on their 50s playing matches. You make a goal post on the street and play, it was a luxury to get a normal (concrete) pitch.
You walk in the school today and you would be lucky to see 10 children play after school. Everything is phones, tik tok, instagram, video games, cafes etc. Who wants to sweat doing dumb sports.
Multiply that for the grind and dedication required for how many years before you become an elite athlete, garnered with non-existing funding, crumbling facilities, not enough knowledgeable coaches and staff in general and you get and optimistic prognosis of 5 medals. And yet, it would still be better, than a huge part of the World. People may laugh, but if we had even 40% of the system and desires from the 80s, we could be fighting for a top 20 in the medal table at least..
(Or you could still say it was only magical potions and mushrooms..)