Just because Adobe is doing the transition poorly (albeit you wouldn't know from their share price), I don't necessarily buy that it's a fundamental flaw in the SaaS business model. Indeed Figma & Canva are both SaaS companies themselves. As MSFT has shown, it doesn't take much for a giant to come back. I don't think Adobe is particularly cash-strapped so they can weather out a bunch of mistakes/internal realignment.
The younger generation will reach for the more affordable options like Figma, Sketch, Canva. Everyone will know how to use these tools a lot better so this these will become the new standards in the workplace.
That's how you build your userbase 5-10 years into the future. That should be a no-brainer.
What's harder to price in a discount with SaaS is how to deal with smaller companies. Startups with almost no money but that could grow into lucrative customers down the line.
This might be less of a problem if they hadn't also slashed education discounts (pupils and students used to get 80-90% discount, presumably to discourage buying used or pirating)