I'd like to preface this by saying that this makes absolutely no sense to even consider if you're not already in the Apple ecosystem with AT LEAST an iPhone and an AppleTV/iPad/HomePod to act as a Home hub so you can control things remotely and have automation that can execute without manual intervention. If this isn't you, then HomeAssistant is the way to go, no questions.
What I wanted to accomplish with my home automation project was to build something that was able to do things like dim the lights when you start streaming a movie, while remaining secure, not reliant on the cloud as much as possible, and controlling and owning the majority of the data involved - I didn't want to have to send all this usage data to some random company in the cloud with a shitty privacy policy. The recent Eufy camera kerfuffle is exactly the type of incident I was worried about and wanted to avoid, if at all possible. You have to have some amount of trust, but the less you trust, the less risk your data is under.
Both Home and HomeAssistant allow you to do this, and while it's undeniable that HomeAssistant allows you to do much, much more than these simple automations, it turned out that I didn't want or need this functionality, but was paying for it with the time investment required to configure, maintain, update, and own all aspects of the HomeAssitant installation.
As an example of time investment that HA requires that Home doesn't is the time required for making dashboards: I spent more time making dashboards look good than I spent doing the initial configuration of all my devices.
Another gap that I found annoying was that HomeAssistaly doesn't have a voice control option. They're working on integrating one now with their most recent releases, and it does work reasonably well, but it's still clunky and far less comprehensive and featureful than just using one directly.
And yes, I know you can integrate Alexa with HomeAssistant currently - and I had several Echos for this purpose - but you're now relying on, again, someone else's cloud and security for all sorts of things in your own home, which is against part of the whole point of building it on my own in the first place.
Worse, the Alexa integration if you self-host is less an "integration" as it is just two parallel home automation products, so now you're maintaining TWO things, one of which is still 100% cloud-reliant, and one which talks to the cloud reliant thing but they both end up breaking differently, at different times, and have all sorts of "fun" failure modes.
One thing that HomeAssistant does that's unmatched is it's ability to ingest all sorts of data ranging from weather, to how much power you've used, to the output of your solar panels and then using it to automate other actions - if you're using more power than you're generating from your solar panels, turn off your AC for example.
I never had ANY meaningful luck, regardless of the time investment, on these automations because too many datasources were unreliable, or would just randomly drop out causing things to either trigger in error, not trigger, or just do silly things that don't make sense.
A prime example is the automation to dim the lights when the TV was turned on and restore them when turned off. Worked great, except that, sometimes, at 2AM it would decide that the TV had just suddenly turned off, and trigger causing a bunch of lights in the house to turn themselves on in the middle of the night which was, most assuredly, not the goal.
So, after nearly 2 years of messing with HomeAssistant, I went looking for an alternative and ran across Homebridge.
Configuring all my devices was relatively painless - the method to add any particular manufacturer's device to one is much the same as the other: same user credentials, same API keys, same tokens. Add the appropriate plugin, configure the plugin (or just edit the single flat JSON file), then add Homebridge to the Home app and bam, done.
The only major difference is that you only need to add the devices that don't already support Homekit; if they have Homekit support you simply add them to Home directly and don't have to worry about Homebridge at all, which meant configuring about half my devices was super simple, and the other half required some work in Homebridge. Still, the time investment to get everything added was about half the time it took to do the initial HomeAssistant installation and configuration.
The automations are also simpler, but very straightforward: pick a conditional, then pick what you want to happen when that conditional is met. Ex. 'when I leave the house, turn off all the lights'.
Ultimately, I have a home automation setup that does what I need, and haven't really had to spend any time invested in maintenance in several months. Which, ultimately, is the goal of home automation: automate things, not spend all your time maintaining the thing that automates things.