I believe Thunderbird is K9’s current beta, rebranded.

There are, unfortunately, some features banks make mobile app exclusive (e.g. Zelle sometimes, check deposit).

I have a spare phone I keep in my drawer for when I really need a banking app.

The support article explains the rationale.

Unchecked by default would render the experiment useless.

1. PPA doesn’t make Mozilla money.
2. Firefox is developed by Mozilla Corp, which can’t take donations. Mozilla Foundation does do fundraising drives, but that’s mostly for their public advocacy (which, ironically, may be where the idea for PPA originated).
3. PPA has a checkbox in about:preferences.

Pixels have had large camera bumps for several iterations, fold or not, like pretty much every phone.

Dishonored is the closest Deus Ex successor in my mind. Harvey Smith in the level design DNA.

I believe Apple still has the power to block third party store apps based on signature. It’s a security thing to be able clean malware.