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Home Assistant, Homey or a closed system
They differ less in capability than in who keeps control of the system, and what happens when a vendor disappears.
This question is rarely about features. What you notice three to five years in is not which one supported more integrations, but who ended up holding control over the system.
Home Assistant
Open source, runs locally, and has an integration for nearly every protocol. In exchange it needs maintenance: updates occasionally break things, and you have to understand the configuration. It is the right choice if you either want to work on it yourself, or have someone to maintain it. The system is entirely yours — exportable and transferable at any point.
Homey and similar appliance controllers
A far easier entry: several wireless protocols in one box with a workable interface. The limit shows up when the automation logic outgrows what the interface allows, or when a device is not on the supported list. The vendor cloud is part of how it works — if that service ends, so do the functions that depend on it.
Closed vendor systems (e.g. Loxone)
Strong built-in logic, predictable behaviour, a proprietary bus — faster for an installer, and more stable than a self-assembled system. The price is vendor lock-in: device choice, pricing and the pace of expansion all depend on the vendor, and modifying the system usually requires a partner.
The practical answer
Most real systems do not choose: KNX or another field bus carries the base functions on its own, with a locally running controller on top providing the logic and the interface. That way a controller outage does not leave the house dark, and replacing the controller does not mean rebuilding the whole system.
Before deciding, it is worth working through what is achievable in that particular building — that is what the remote consultation is for.