Correctly installed wire nuts on solid core are totally fine electrically, though still less user friendly to work with compared to WaGo connectors.
The main challenge is that installing one correctly isn't the easiest thing ever for most DIY installers, and even certified electricians don`t get them right 100% of the time. Wago connectors by contrast are so incredibly simple to install and uninstall that you need to go out of your way (and deliberately go against instructions) to do it wrong and create unsafe connections.
That said, if you find any more used Wago connectors in your house save them for later. You're bound to come across a situation eventually where you'll struggle to thread on a wire nut correctly, and you can thank me later after troubleshooting your intermittent connection.
I wouldn't be surprised if that becomes a thing. Black mirror here we go!