I keep telling them that Google spies on you, but they don’t care because it is free and it works.
How reliable are these providers and what are the chances these providers emails would bounce or go to spam when sending an email?
They found a deal that seems to be ok for them. To get them to change providers, you need to suggest one that would be a better value, and to be honest, I don't think you can find one.
As much as I don't necessarily like it, I think we have to put a price on our privacy and personal data. And for me, paying for the Proton family plan seems like a good trade-off, at least for now. So far, I haven't got any emails to bounce when using the @pm.me or @proton.me email addresses, except once (I forgot which web site).