Are you sure the “Athens Riviera” is what you are looking for?
It's a coastal area located roughly between Glyfada and Vouliagmeni, full of resorts, often high-end, located along the coast, along a large avenue (almost a highway) with 4 or 6 lanes. A large area near Athens, around the former Athens Airport, is currently the biggest construction project underway in Europe, the "Ellinikon."
This video will give you an overview of this coastal area:
https://youtu.be/1-UQcuiTkZY
We went there two months ago to go further east in the region by car, it's still like in the video.
In my opinion, if you're using Athens as a base, you'd be better off staying away from this area. Rent a car and, for example, go to Cape Sounion (or even further to Lavrio).
If you like peaceful places, there's also the Kaisariani Monastery on Mount Imittos, which can be a great day trip.
It's a 30-minute drive from the center of Athens. .
https://takemetogreece.com/kaisariani-monastery-athens/
https://maps.app.goo.gl/qeaQ5t68FzTdTfvFA
And of course Athens is not just the Acropolis and Plaka, there are plenty of other places to see. Enough to keep you busy for a whole week.