If ad was the only way to get money, there would be no product/service to sell anymore and thus...nothing to advertise. It just cannot work that way.
Photopea is lucky that it has a decent amount of revenue. But that's an exception, not the norm. Generally speaking, for new software, the business model of desktop, client-only software hasn't worked well since late 2010s at least, and nobody should expect to run a viable business like that today. There are very few applications you "install" on your computer that doesn't require native capabilities in some way.
The real engineering work that will always be paid for is identifying problems and testing solutions to see what solves the problems.
The substrate in which we use to do that will change, but the job will endure.
Those that just do what they are told however, yeah they are SOL unfortunately.
Creative problem solving is the only skill that will matter anymore.
If security is a solved problem then anyone that wants to teach themselves enough can move to trying to solve disease, until disease is solved, then we all move on to building enough robots to mass produce enough food to solve world hunger and shelter... and once the needs of everyone on earth are solved at an ever cheaper price until it is free... then I guess we do whatever we want.
I feel like trying to better humanity, even if I fail, is a better use of my time than simply saying nothing can be better and giving up. At least by failing well, at worst, the next delusional person can carry the work forward learning from my mistakes.
It is going to be a slog, likely over multiple generations, but one worth the climb.
If you have the capacity to do that, I.E. a multimillionaire, then sure.
Capitalism is just a bootloader to get us there.
Humans once built things to benefit society over multiple lifespans.
That is not the things that can be unlimited. There will always be better food, bigger houses, better medicine etc.
In the eyes of the bottom 30 (or maybe even 60) percent of humans on the planet Earth average American already has the access to unlimited food, shelter, medicine, and knowledge. But good luck to convince Americans that they have those access.
It's not. The economic landscape is also entirely different from before as well.
Doubtful when stock prices go up because companies lay off/fire employees.
Doubtful when hiring foreign workers for cheap is strongly preferred over their own citizens.
If you're already a millionaire now invested in tech and S&P500 and have property maybe you'll be alright and maybe you won't agree with this perspective, but my perspective applies to the vast majority of people.