I've been asking myself this question a lot, and I don't have a perfect answer, but here is what I am seeing so far:
We are moving from a period of time in which engineers were needed to do, essentially, day-to-day grunt work of software development (write this CRUD app, figure out this schema, implement these requirements) to a period of time where engineers will be needed to oversee, design, and manage relatively intelligent tooling that will do those things for us, and then be evaluated on its results.
Put another way: Engineers are currently like factory employees at the turn of the 20th century. Lots of manual tasks are needed to keep our "factories" running, tasks that, in the 21st century, robots can do just as well. But that doesn't mean no humans work in factories. Plenty of people do, but what they do are the things that the machines can't be trusted to do alone, or at least, can't be trusted to do alone sufficiently reliably for reasonable cost.
But even so, far fewer people work in factories now (as a proportion of the population) than did in the early days of the industrial revolution. It seems to me that engineering will likewise be winnowed down. That means that ultimately even the most valuable engineers won't be as valuable. You won't need as many of them to do the work, and you won't need to pay them as well.
If I choose to stay in engineering (which is by no means a guarantee), I think I will need to focus on moving from "day-to-day implementation" into "designing and monitoring the overall approach to systems." At most organizations, this means getting to and being successful in, at minimum, a staff engineering position, preferably higher (e. g. lead/principal). I am nearly there at my current organization, but I don't have the skills to perform at the next level yet. I can probably develop them, but that's also not for certain, and even if I do, I might not like that kind of work.
In that case, if I wish to remain in the workforce I will need to change career fields, and find one of the things that won't be automated away by LLMs or similar technology over the next 15-20 years. (For example, contrary to a lot of thinking currently, I think a premium will continue to be placed on genuine human creativity; I don't think AI will eliminate the desire for humans to consume art created by other humans. Any field which involves physically doing - such as the trades, or maybe some kinds of hardware engineering - would also be an okay bet.)
Or I could always coast on the coattails of my spouse, who is already in such a field. That might be easier :)