The same thing goes for small surface mount stuff. Ex. I was looking at using a TSSOP package for a project, but I just couldn't justify the cost of ~10$ a chip when I was unsure I could even solder it. Even for my last project, I messed up a few boards because I had trouble soldering the leads for the Micro-USB connector on it.
On the topic of 0402's, I agree I could probably solder them with enough patience - though that goes back to the risk issue, if I can't then I blew a bunch of money on boards I can't put together. For my projects, I thankfully haven't yet run into a situation where I needed to go that scale, so the lowest I've gone are 0805's, which are nice and chunky.
And to be fair, I don't really know what qualifies as "professional level", I'm mostly thinking of things like computer motherboards, phones, smart watches, etc. Tons of things have PCBs in them that don't require that level of detail, and I don't know the percentages of people doing each - perhaps there is a decently sized professional market for a tool that can do smaller boards with less layers/complexity much smoother.
Can we put a number on the cost?
Seems to me like if you want a "serious amateur" electronics lab for doing things like prototyping boards with BGA components then you need a budget of around $300 - $1500. Price depends on whether you want cheap-and-cheerful starter kits that will eventually be replaced verses professional stuff that ought to last for decades.
On the one hand that's real money but on the other hand that's also what it costs to buy a new laptop or travel to a conference.
And yeah, I was considering going into that but didn't want to talk too much out of my knowledge zone. There is definitely a huge divide between the professional PCB designers and what hobbyists (like me) tend to make. My most complicated board is a 2-layer with mostly through-hole and a few surface-mount. BGA, the really small surface mount parts, any anything crazier than maybe 4-layers is just completely out of my reach - I could theoretically design them with a lot of learning, but the expense of getting the design fabricated and the impractically of soldering them manually just makes it a complete non-starter. But yet, those parts are pretty much all that you'll see on modern boards. What I'm doing is so much simpler than what professionals are doing it's really not comparable. I mostly don't need the complexity of something like Eagle, but for companies doing modern PCB design those complex features are an absolute requirement.