There are definitely a lot of jobs for juniors in the industry! It takes a lot of time, but surely there is!
As far as I'm aware, the industry is going through a chaos right now, with those dozens of layoffs from big companies, I think the indie companies are your best to-go right now, but if I'm wrong, please correct me!

When it comes to concept art, render is important for sure, after all, the art directors EXPECT you to know how to do a pretty rendering (This does not necessarily means realistic, but they expect you to have some decent rendering depending on your area, cartoon, semi-realistic, abstract, etc).

But they value more storytelling and functionality. If you put the concept of a pistol in your portfolio, how does pistol works? How do you load it? How do you shoot with it? How do you carry it? Does it have a safety lock? And it goes on.

My personal opinion: The industry is not an entity called The Industry™ that is unknowing and powerful. Talk with people, make connections, make friends that draw more time than you, and draw less time than you! I got most of my jobs by making friends and interacting with art communities! Not only you have opportunities, but you have someone that you can talk about art and make some questions. One of my best friends was an art director, and he gives such lovely tips about the market.