On the contrary, Junior positions will be more and growing because now you do not have the fear of Juniors being liability for a while as with very little guidance they can get stuff done while Seniors keep an eye on bigger things and have free time not being spammed by n00b queries.

Also, given the saturation of STEM graduates now, you have proven group of juniors who can learn themselves over expensive lottery of bootcampers who might bail out the moment it is no longer the surface level React anymore.

With AI, more tiny businesses can launch into market and hire juniors and part time expertise to guide the product slowly without the massive VC money requirement.