I find it far more likely that ECAD industry will go the way of Blender where the high cost of per seat licensing will drive big companies to start contributing to open source alternatives to stop the bleeding. Given the diversity in needs of different industries, each could contribute the pieces they need into a whole that makes up a viable competitor.
The bigger problem than the number of hobbyists is that the vast majority can't even afford to prototype the high end of what PCB designers can do. For example, a 12-24 layer board with mixed RF and 1ghz+ digital signals (like the hundreds of smartphone main boards connected to a camera that are design each year) can cost thousands or tens of thousands to fab in small quantities, let alone assembly and parts to put it together.
Edit: And to your latter point (and it is a reasonable one), the HackRF was done in KiCad. This demonstrates that something at that level of complexity can be done with open source tools and still make enough profit to be open hardware. Promising!!!
That's a very interesting point, I do agree that could happen if enough companies are unhappy with the price, though that's not something I know much about. The price of switching to a new tool would be very high though, I would think, so any viable competitor needs to be very feature complete and probably needs a high degree of compatibility with whatever tools they're currently using.
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.
You can solder 0402 scale stuff with a pair of tweezers, a $20 USB microscope and a regular soldering iron. 4-layer layout is actually easier than 2-layer, it means less track gymnastics required. This kind of stuff could qualify as 'professional level', a good choice for all kinds of general boards (sure, not smartwatches probably).
For me, the biggest limiting factor is not really skill, but cost. I can theoretically do all of these things, but the cost tends to be prohibitive and the risk too high. 2-layer boards are the best and 4-layer boards are my limit because going any higher just goes way outside the price I can justify putting into hobby projects that may not pan out. 2-layer boards you can sometimes get on sale dirt cheap (ignoring shipping...), and the mark-up when going from 2-layer to 4-layer tends to be at least 2x, and for most places I've looked at more like 4x or higher.
The same thing goes for small surface mount stuff. Ex. I was looking at using a TSSOP package for a project, but I just couldn't justify the cost of ~10$ 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.
> the biggest limiting factor is not really skill, but cost
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.
The bigger problem than the number of hobbyists is that the vast majority can't even afford to prototype the high end of what PCB designers can do. For example, a 12-24 layer board with mixed RF and 1ghz+ digital signals (like the hundreds of smartphone main boards connected to a camera that are design each year) can cost thousands or tens of thousands to fab in small quantities, let alone assembly and parts to put it together.