In practice the vast majority of designers are using Mac, so it's not like it not being cross platform was the problem.
The thing that made Sketch lose against Figma was that they never really tackled the issue of collaboration until Figma came along, leaving it for 3rd parties like Invision and others to solve.
Now they have most of the collaboration features they were missing, but by then it was too late and Figma had all the mindshare.
But if Figma keeps following this route, who knows. We might see Sketch grow in mindshare again.
Perhaps my perspective is skewed because I've only been on small design teams during the rise of Figma – but my view is that "multiplayer" was always a sell-to-managers feature, and at best an annoyance for designers.
Why Figma won is, at least in my own experience, due to two areas where they roundly beat Sketch: auto-layout and performance.
Auto-layout was one of those squandered first-mover advantage stories: Sketch had it first, but built it into the symbol/component system and never envisioned it as a global feature. Figma did, and it was a total game-changer. Overnight, everything else felt like using Photoshop in comparison.
Why couldn't Sketch just generalize its own auto-layout feature? They finally did (only about three months ago!) but I suspect it had to do with Sketch's architecture, which leads into the second Figma advantage: performance.
From the start, Figma turned the native-app-versus-web-app intuition on its head. Being browser-based, it should have been much slower than Sketch... but due both to Sketch's legacy as a general-purpose vector graphics app and Figma's stellar engineering org, Figma was leagues faster when it came to the kind of big, complex files design orgs deal with on a daily basis.
Between these two things, the writing was on the wall. I hope Sketch has a chance to come back, though – missteps like Dev Mode give them an opening now that they've had several years to catch up.
The Mac-only support wasn't an issue. I love Sketch, and I used to like it more than Figma. What happened is that Figma resolved many things that were a headache with Sketch:
- No more file-sharing issues. Designers are not good at using tools like git. I used git+lfs to store my designs, but most of the design team used Google Drive or Dropbox. In both cases, you end up in a situation where the file you are looking at is not up-to-date. Figma removed that issue.
- Design reviews: Collaborating on the same design as in many Figma demos is rare. However, playing with the design in a remote session is common during a design review.
- The pace of updates: Figma moved faster to improve the editor's UX. The auto-layout, styles, components, and variables are good additions to everyday work. It took Sketch a while to update the editor's UX.
There is no return once the team purchases the Figma subscription instead of renewing Sketch. When I started using Figma (around 2019), I hated its slowness and missed some Sketch features. Our UX team adopted Figma, and only a few designers continued using their Sketch license (I was one of them). But, it didn't make sense to not align with the rest of the team (for the reasons mentioned before). I haven't used Sketch since then. Sketch added many sharing features, but there isn't a solid reason to go back and convince the team to migrate their designs.
I really really love Sketch, and for all the reasons that make it different to Figma.
I just hope they don’t go too deep into Figma’esque cloud features (at least without being able to opt out) because Sketch is a really superb standalone piece of Mac software and I appreciate it for that.