Sorry, but now this is starting to sound like sour grapes.
Ok, they got a good amount of funding. But that alone is not enough to justify how they managed to gain as much mindshare as they did in relation to XMPP.
Element's funding in 2018 or 2021 did not steal any opportunity for (e.g,) snikket to work on their product. Element following the "cathedral" model allowed them to be faster in the development of multi-platform clients, while the XMPP devs were all fixed to the Bazaar ideal, and because of that absolutely failed to deliver a modern application in the platform that is used by half of mobile users in the US.
We (techy types) tend to ignore things that end users care about and we are a lot more forgiving with systems that we see as "technically superior", but the market cares a lot more about things like "Can I send emojis without having to worry about what client people use?" then "synchronization model or disk space requirements".
This is not just "marketing", this is "having someone with actual business and product sense".
If it was up to me, sure I'd wish that more people would be using XMPP. But in 2019 when I told my parents that I wouldn't be using WhatsApp anymore and that we needed a different app if they wanted to have video calls and see their grandchildren, XMPP was not even a choice for my iOS-using father, and Element (née Riot.im) was at least usable.