The problem isn’t that the client keeps changing half so much as the network keeps changing. Clients either keep up, or they don’t, and if they don’t, they break, just like Telegram Desktop. Any Matrix client would need these kinds of continuous updates to avoid potentially becoming totally unusable at some arbitrary point in the future, regardless of which client we picked. Additionally, Element is the only client I know of that has a company behind it to drive development, the other clients might become unmaintained whenever the devs stop feeling like maintaining them.
This is a bit similar to the issues that web browsers in general face - there’s so much to implement that only well-established browsers can really keep up. Handling the basics of the protocol doesn’t seem to be too hard, but once you get into the nitty-gritty (encrypted DMs, single sign-on, threads, handling room scrolling without jumping all over the place, etc.), it becomes a massive job. At the moment Element and forks thereof are the only Matrix clients that are good enough I would consider them daily-drivable for the average user. To my awareness, the only client that is mostly feature-complete that isn’t an Element derivative is Nheko, and IMO Nheko’s UI/UX is really, really bad. (I had an easier time learning Vim than I had learning Nheko.) Nheko also has a security warning about encrypted DM handling, which is slightly concerning:
The current implementation is mostly stable, but it was never audited. If you rely on it for security, we can’t make any guarantees.
It might be, but the sad thing is Element Web cannot be used to search through encrypted chats. You have to use Element Desktop or some other client if you want to do that. The user experience of having Element in a tab is also less-than-awesome, and Element’s browser support is rather lacking (even Firefox has issues with it if you try to use it in a private browsing window, for instance).