I'd like to recommend a light switch solution to my non-technical business partner for his house in the US and it needs to be hub-less (due to his lack of technical abilities and also because I'll end up being his tech support if he can't set it up himself).
What he wants to do is replace the light switches with something (i'm thinking WiFi to avoid needing a hub) but he also wants to add some additional light switches around the house without having to wire them (battery) that would then able to control the other wired WiFi switches.
Hue seemed the way to go but that would mean a lot more $ for all the down lights. It really needs to just be an app.
Get a Caseta Pro bridge. The app is very friendly and easy to use. This provides wired switches that will always work and Pico remotes which are battery. They can be mounted on the wall or pedestal stand or just lying around.
If you go with Wifi there's always going to be some issue that can and will come up. A Lutron system is the most reliable you're going to get.
The Lutron Caseta Smart Bridge Pro2 is the current model Lutron is selling. It adds support for Apple HomeKit, which may be useful to the OP's business partner. Also, the original 'Pro' model is only available via 3rd party sellers these days and cannot be activated with Lutron's servers. Lutron support will often replace it for free with the Pro2 model.
Also, the Pro/Pro2 edition is needed for Hubitat's Telnet integration. But since the OP was trying to avoid the use of a Home Automation Hub, technically telnet is not required, but might be a good idea to future-proof his investment, as @rich.princeau pointed out.
So, the best advice is to get the Lutron Caseta Smart Bridge Pro2, IMHO.
I also love that Lutron has integration for Amazon Alexa, Google Home, Logitech Harmony Hub, SmartThings, Apple HomeKit, etc...