I spent years and a fair chunk of cash trying and failing to get a reliable zigbee and z-wave network set up using various bits of kit.
To echo the article, the problem with zigbee & zwave for me was that things would stop working, and it was almost impossible to work out why. The only "solution" was to start the annoying repairing process as outlined in the article which was a huge ballache.
In the end I also binned all of the zigwave & zwave bits and moved to a 100% wifi-based solution using MQTT & Tasmota firmware (1) running on very cheap hardware that is usually very reliable - I don't think I have had a single unexplained outage in the couple of years I've been running this now. Wifi + MQTT is mature and just works. It is also super easy to diagnose problems - you can see the devices on your network, ping them, subscribe to their MQTT topics, manually send messages on MQTT etc. Its a dream compared to the black box of zigbee & z-wave where you essentially had zero control apart from on/off.
Wifi + MQTT + Tasmota appears to be the solution for me.
My main complaint now is that HomeAssistant cant connect to Google Home/Alexa (so that I can use voice control), so I am using OpenHAB (which has a free integration that works). OpenHAB seems absurdly complex though, and they seem to be in a continual process of rewriting the software (some stuff is stored in config files, some in a databases, and the location of the config files is not in the docs/the docs have the wrong location so backups are hard, the docs are only for V1 (but don't say that they are only for V1) but the current version is V2 that is also deprecated because they are working on V3 etc, the recommended UI can't do everything you need to do to get the system working so you have to manually update stuff in a shell but the aforementioned docs telling you what file to edit are just plain wrong etc because the are referring to some different version, running OpenHAB in docker requires some odd permissions/user set up on the host machine etc - it is a mess). I am planning on ripping out OpenHAB and replacing with NodeRED at some point since that seems sane.