Adobe's software is pretty bad and John already listed most of the reasons (they have no strong incentive to innovate or take risks, they are an old company with code some code bases older than 30 years, so naturally hard to maintain and work with, poor understanding of actual end users), but then again, it's not like the competition is that much better either.

Sketch fucks so many things up with every tiny update that people are scared to update and you get whole threads here on DN trying to figure out what's still working, it has its own set of bugs and quirks and the advantages are only marginal.

Affinity Designer is pretty fast and performant, but it's essentially just PS/AI with a modern code base, it can't do anything new and is not on feature parity with Adobe Software.

XD is taking ages to add even basic features so adoption has been slow, but with Adobe behind them, it is growing, maybe in a few years it will be usable.

I'm still not sure what Figma's deal is, but it's a web tool so I'm good.

The new tools all seem similar to each other and not really bringing anything all that impressive.

So I guess it's a really tough problem to solve too, it's not just that Adobe is rubbish.