> There's a dead comment under here which points out that 3.5mm is three connections around a large-ish cylinder, while USB-C is 24 connections in a tiny space.
That's not it really. It's the connector and solder strength.
The problem is that when you buy a piece of electronics with a micro-usb port, you don't know which connector type the product designer used, or if the solder joints are good, etc. Sometimes you won't know for maybe 100 or 200 insertion cycles, which usually places the device outside a manufacturer's warranty.
The solder joints on a right angled jack experience a torque on insertion. That torque puts strain on the solder joints. Do it enough times those solder joints will crack from the cycling.
Or worse the connector just rips the copper up off the fiberglass layer, since the strength of copper bond to fiberglass is much much less of the strength between solder and copper.
Here's an example of an SMD mount only micro female usb connector:
https://tinkersphere.com/electronic-components/1817-female-m...
The only thing holding it to the circuit board itself are tabs which need to be soldered to copper pads on the board.
(My failed headphones were of this type.)
Though it seems like most USB C devices appear to be using through hole legs for mounting (I haven't seen a device use surface mount only yet). The solder flows through copper plated hole, bonds with the copper in the hole as well as the copper on the opposite side as well as the leg in the hole, increasing the strength of the part.
https://www.mouser.com/Connectors/USB-Connectors/_/N-88hmf?P...