Matrix tries to kill XMPP but the reality is that if you want to self-host, XMPP is much less of a hassle. Also, Matrix is an open standard as in “pay big money to participate in the openness”. https://matrix.org/blog/2022/12/01/funding-matrix-via-the-matrix-org-foundation/

Membership comes at various levels, each with different rewards:

Individual memberships (i.e. today’s Patreon supporters):
    Ability to vote in the appointment of up to 2 ‘community representatives’ to the Foundation's governing board.
    Name on the Matrix.org website
Silver member: between £2,000 and £80,000 per year, depending on organisation size
    Ability to vote on the appointment of up to 2 ‘Silver representative’ to the Foundation's governing board
    Supporter logo on the front page of the new Matrix.org website
Gold member: £200,000 / year, adds:
    Ability to vote on the appointment of up to 3 ‘Gold representatives’ to the Foundation's governing board.
    Press release announcing the sponsorship
    1 original post on the Matrix.org blog per year
    Participation in the internal Spec Core Team room
    Larger logo on the front page of Matrix.org
Platinum member: £500,000 / year, adds:
    Ability to vote on the appointment of up to 5 ‘platinum representatives’ to the Foundation's governing board.
    1 sponsored Matrix Live episode per year
    Largest logo on the front page of Matrix.org

Matrix is daaaaamn slow. And not private.