I was going to say this @anon62610374, until I saw it had already been posted!
It probably does work quite effectively to build trust that it’s a “proper financial product” rather than a fly-by-night operation.
Mastercard won’t let just anybody give out cards on their network, you do have to commit to all the rules around chargeback, etc.
Customers do vaguely realise this, so it adds some credence and helps them realise that their money is protected to an extent, encouraging usage.