What your forgetting to say...
Well I personally have in a previous life had to do a ton of graphics and all I have to say after starting with paintshop pro then moved onto photoshop and now use a combo (depends on what type of graphics, raster/vector) of krita/inkscape/gimp and honestly I can say with confidence the people you are talking about are lazy. There I said it, they have memorised how they do things and don't want to learn something new... its like people today think that things stay static for ever.
Hell even artists at one point want to "use new mediums" so anyone expecting things to stay the same for ever is deluding them self.
As for CAD, circuit design, and MATLAB equivalents there are plenty and having done some circuit design in college I can tell you with certainty that these days the big boys out there do offer a *nix version cause Windows is just not stable... now before any winhead comes in bitting about this isn't true I can say 30 years into IT that windows is not stable and it has cost the world trillions in lost up time support costs and lawsuits (data breaches) so yeah. And don't tell me "but windows 10, blah blah blah" guess what Windows 10 has had how many "Feature" updates that have borked system world wide so nope not only does it crash by it self the vendor just for good measure add more crashes so there
There are plenty of OSS tools to do everything with the same quality as any proprietary product, the one thing I can say that sucks though about OSS is the documentation (although mostly better these days) is horrible in comparison. Often written by someone who actually doesn't use the app they developed I say this cause when have you actually seen a useful example given, if there is one at all they always give usually one or two of the simplest use cases that no one every uses cause use cases are often complex but there are common complex use cases. So yeah that is where OSS sucks is user guide documentation not how to setup documentation that is usually okayish, but documenting all switches (like man pages right) and common use cases needs vast improvements.