I'm not 100% certain but I'm pretty sure you don't know what you're talking about.
There are several types of components that require surface mounting on PCBs. By far the most common are things like resistors & capacitors that are machine placeable. But others, like BGAs and through-hole components, often require hand placement because they require hand soldering and can't go through a wave solder machine. Additional possible complications are boards with components placed on both sides, or multi-layer boards with non-standard solder. Finally, Debug/Repair stations are always manual.
Source: Masters in operations research and 15 years experience writing factory control software for one of Foxconn's direct competitors & largest trading partners.
BGAs are nearly impossible to hand solder. You can theoretically do it by flipping them upside down and soldering individual wires to each ball, but this is very difficult, unreliable, and harms signal integrity. It's completely unsuitable for production and even for prototyping it's basically never done.
Through hole components are commonly hand placed or hand soldered because there are only a few on the board, not enough to make machine placement/wave soldering cost effective. Additionally, some through hole components have shapes that make machine placement difficult.
Generally, increasing automation requires some design changes, but you can start with the same basic design and end up with one focused on automation and another optimized for human asembly. So, it's a little more nuanced than you are suggesting.
PS: There are also at least demos of pick and place for through-hole components. But, I don't know how production ready they are. (Manufacturing PCBs is not my area.)
There are several types of components that require surface mounting on PCBs. By far the most common are things like resistors & capacitors that are machine placeable. But others, like BGAs and through-hole components, often require hand placement because they require hand soldering and can't go through a wave solder machine. Additional possible complications are boards with components placed on both sides, or multi-layer boards with non-standard solder. Finally, Debug/Repair stations are always manual.
Source: Masters in operations research and 15 years experience writing factory control software for one of Foxconn's direct competitors & largest trading partners.