I stayed at Renata's apartment in Copacabana for 2 months. This place is perfect for a solo traveler or a couple. It's not the biggest apartment but it has everything you need and the location is perfect (right next to the Metro Siqueira Campos station and a short walk to the beach). The wifi speed was excellent for those considering working remotely (I regularly measured download speeds of 60 to 100 mbps and sometimes even faster). The apartment is located in a mall structure and you have a supermarket, coffee shops, bars, restaurants, laundromats, and basically everything you need right outside of your apartment. If I return to Rio de Janeiro I will definitely contact Renata to stay at this apartment or one of her other apartments in Rio.
And speaking of Renata, she is the best host I have encountered while using Airbnb. She responds promptly to any questions or concerns. She had great advice and recommendations. She helped me get Carnival tickets, set up a covid test appointment for me, located businesses for me when I couldn't find them, and moved me to a new apartment when the building had some rooftop construction work going on and the noise was too much for my remote work situation. She provided top notch service and I highly recommend staying at her apartment if you are looking for an affordable and well run place to stay in Rio.