From what you’ve said, I’d guess that the devices your controlling aren’t all in the same physical location within your house.
My solution in that situation is to have multiple remote devices that all talk to a central server which in turn talks to Blynk.
I currently have 19 (I think) different devices scattered around my holiday home here in Spain, that all connect to Wi-Fi and talk to the central server using MQTT messaging. The server is a Raspberry Pi which uses Node-Red to handle the logic of how the devices talk to each other, and a interfaces with Blynk, Amazon Alexa, IKEA Tradfri etc.
The system has more resilience the because failure of one single device will have a limited impact on things (not that I tend to suffer failures), and it allows control via multiple devices (a Nextion touch screen for heating/cooling, Amazon Alexa, 433MHz remote controls, Blynk etc). If the internet connection fails then the core system keeps running and can still be used effectively.
For me, this works much better than having wires running back to a central Arduino that acts as a hub. It’s much easier to expand, and troubleshoot, and its much more portable. I have devices that operate via solar power that are situated in locations that would be very difficult to hard wire. Doing a quick count I interface with 21 relays, 3 blinds (via 422MHz), two temp/Humidity sensors, a weather station, a solar charge controller, an RFID reader, 3 PIR detectors (via 433MHz) and the Nextion touch screen.
My Raspberry Pi is a single point of failure, as is my router, and I mitigate this by having spares that are pre-configured and can quickly be swapped for troubleshooting or replacement, not that I’ve ever had cause to use them.
The ESP8266/NodeMCU/ESP32 devices can all be updated remotely via OTA, so I can sit in my armchair and fiddle with the code then upload a new sketch (which is when I tend to create problems for myself!). An Arduino connected via Ethernet or Wi-Fi can’t be updated in this way.
So, I’ve tried the Arduino Ethernet approach, and had a brief excursion into the Arduino/ESP-01 approach, but for me the standalone wireless approach is far far better.