They used to be, they filled an unmet need in the design tools space (clickable prototypes) for years. Lately tools for interface design (Figma, Framer X, Quartz Composer, Origami, etc) have Invision’s main feature baked into their software (where the work is being created) so there‘s less need for designers to use it. Invision intended to get into the creation tools market, but suffered a poorly-managed rollout of their application, and has been floundering since.

They also had a fairly drastic price increase that made our company scale licenses back to only designers, which has reduced the collaborative aspect it once had.

Even UI developers often get exposed to Invision, especially if mobile is involved - it’s a very useful tool.

I'm not working on much front-end these days, but as of 2/3 years ago InVision was the best option I was aware of.

They're pretty big and got into the design tools game early on