Is Figma enough for UI/UX designers?

Yeah, so if you're looking for the TLDR version, here's the only GIF you're going to need:

To expand on that previous point (it's a joke): if you're just starting as a designer and you're wondering which tools you need to know and which apps are the industry standard: right now it's either Figma or Adobe XD, but Figma is the better and preferred alternative.

Yes. Figma is great for user experience work, prototyping, wireframing, doing anything which involves understanding user's behavior. You can do all this directly in Figma or you can use a sub-tool called FigJam which has a lot of useful templates that ease up the workflow.

Figma is obviously excellent when it comes to user interface design - after all it's the industry standard for a reason. The tools Figma offers, the prototyping, the community behind it and the plugins are well polished and with enough dedication you can create really complex designs and layouts. 

Is Figma enough for UI/UX designers?

Yes! Figma is currently the best tool to use for designers. 
BUT - as a web designer you need to understand a few things about your end user. This means you need to have basic knowledge about how websites work, some front-end coding definitely doesn't hurt.

Knowing how to create interactive animations are definitely a plus, even though you can animate in Figma too with a few plugins. 

You can collaborate with other designers, you can share interactive prototypes with your clients trough url links. What's else there to be said: Figma makes the world a better place.  

But on a serious note: if you have 2-3 years of experience working with Figma, I don't see why clients will hesitate to hire you. As a designer as long as you have a solid portfolio you can use Paint for all they care. This is mostly the case for freelance work. 
For full time work usually employers prefer you use Figma and not Paint. So, yes: Figma is definitely enough for UI/UX designers.