I'm still wondering if Wi-Fi mesh or a new and more powerful Wi-Fi router is best? 🤔
Mesh network is probably your best bet if you're suffering from a weak signal. A more modern router won't solve your problem. WiFi routers are regulated by the FCC to keep it to its design: to use for local area networking, so they are bounded by specific specs, like frequency and transmission power. The short wavelength of a 2.4 / 5 Ghz WiFi signal is inherently limiting, so adding more nodes is far more effective.
Also, your devices are half the problem. Even if you find some amazing router that boasts crazy range, it doesn't really help because your phone, computer, and IoT hardware can't transmit to the router at a higher power to match its range. They're limited by power constraints of batteries and poor antennas. Best to put mesh nodes close to your devices.